Class for SSCC 1703 - Group VIIA by SHEELA CHANDREN

HANIS SAFIYAH BINTI MOHD AMIN

2021-01-14 04:24:47 UTC

Thank you dr, for the explanation.
Here are my summary :

- For group 7A or we called it as halogen group, it is consist of fluorine, chlorine, bromine, iodine and astatine.
- this halogen group can be found as salts due to its high reactivity.
- the electronegativity is decreases down the group.
- X need only 1 electron to achieve noble gas configuration so they can form single bond diatomic molecules in the elemental state.
- the melting point of this group will be increases down the group due to the increase in Van der Waals forces and also it size of molecules also will be increases down the group.
- due to fluorine is the highest electronegativity, it can easily remove an electron nearby atom.

The preparations of elements
- fluorine can be obtained by an electrolysis of HF dissolve in molten KF
- chlorine from electrolysis of molten NaCl in Downs Cell or electrolysis of brine in Kellner-Solvay method or Chlor-alkali cell
- bromine can be extracted by passing chlorine gas into concentrated sea water

The application of elemental halogen
- fluorine mainly used as fluorinating agent for organic compound
- chlorine used in the manufacture of organic and inorganic chemicals, paper bleach, water treatment and cleaning and sanitation
- bromine is mainly utilize in the manufacture of organic chemicals
* halogen is oxidizing agent due to it high electronegativity compared to other elements
* the halogen group (except for fluorine) can react with water in disproportionation reaction.

Hydrogen halides
- HF prepared industrially by the reaction of fluorspar with sulphuric acid.
- HF used in the manufacture of aluminium fluoride, boron trifluoride, uranium tetrafluoride and ammonium hydrogen fluoride.
- for HCl, HBr and HI can be prepared by direct reaction with hydrogen and halogens
- the uses of HCl is pickling of metals, acid treatment of oil and gas wells, and others
- in laboratory preparation, can be prepared by the reaction of halide salt with concentrated sulfuric acid. But not suitable for preparation of HBr and HI. So, for that, the reaction of phosphoric acid with halide salts in the presence of P2O5 can be used for prepare HBr and HI.
- the acid strength of HX down the group is decreases.

Oxoacid of halogen
- Cl,Br and I can form 4 types of oxoacids
- hyphohalouc acid (HOX) have oxidation no of +1 , can be prepared by hydrolysis of halogen (disproportionation reaction)
- halous acid (HOClO) with oxidation no of +3, can be prepared by reaction of chlorine dioxide with hydrogen peroxide in the presence of barium hydroxide
- halic acid (HOXO2) with oxidation no of +5, only HOIO2 can easily prepared by reaction of iodine with nitric acid
- perhalic acid (HOXO3) with oxidation no of +7, for Cl and I can be prepared from catalytic oxidation of the corresponding halite followed by the addition of a strong acid.
- the acidity of the oxoacids can be effected by the number of lone oxygen that attached to the same central atom (not oxygen that attached with H)

Uses of oxyanion of halogens
- NaClO3 is converted to ClO2 which is used as bleaching agent for paper culp
- NaClO3 as defoliant and herbicide
- KClO3 as primary oxidant in fireworks and matches
- KClO3 as a source of obtaining oxygen gas in laboratory experiment
- IO3- as a source for production of iodine
- Potassium iodate as a primary standard solution for the determination of iodine.

MUHAMMAD DANISH BIN MOHD ARIF

2021-01-14 04:35:09 UTC

Thank you dr for the class and video of group VIIA. Here are some summary of group VIIA

Group VIIA
- found as salt of halide ion because high reactivity
- fluorin(cryolite), chlorine(rock salt), bromine(ocean), iodine( natrium iodate)
- physicochemical properties: has 7 valence e, down the group increase in melting point, boiling point, size of molecules, and strength of Van der Waals forces
- chemical properties: oxidizing agent, reaction with H2S, reaction with water, reaction with alkali solution, react with non-metalic form covalent bond
• Fluorine
- only has 1 oxidation state, highest electronegativity, isoelectronic with noble gas
- preparation: in industrial, by electrolysis of HF dissolved in molten KF
- application: fluorinating agent
• Chlorine
- preparation: electrolysis of molten NaCl in Down cell, Kellner-Solvay method/ Chlor-alkali cell
- application: water treatment, cleaning and sanitation
• Bromine
- preparation: react bromide ion with chlorine,
- Application: manufacturers organic chemicals
• Test to identify halide ions
: add conc. H2SO4 and heat, add AgNO3 followed by NH3, add Cl2/ acidic NaClO and CCl4
COMPOUNDS
• hydride
- HF: industrial preparation by reaction of fluorspar with H2SO4, in lab react halide salt with conc. H2SO4/ react H3PO4 with halide salt in P2O5
- used of HF: pickling stainless steel
- HCl, HBr, HI: preparation by direct reaction of H2 and halogen
- used: HCl( pickling metal), HBr
- physical properties: down the group, decreases in thermal stability and increased in acid strength
• oxoacid
- Cl, Br and I form 4 types
- hypohalous acid, halous acid, halic acid , perhalic acid
- F form 1 type (because difficult to oxidize)
1. Hypohalous acid (+1)
- disproportionation reaction
- strength of acid: HOCI> HOBr> HOI
2. Halous acid (+3)
- HOCIO stable than HOBrO and HOIO
- HOCIO prepared bt react chlorine dioxide with hydrogen peroxide in barium hydroxide
3. Halic acid(+5)
- only HOIO2 easily prepared
- prepared by react iodine eith HNO3
4. Perhalic acid(+7)
- strong acid and powerful oxidizing agent
- HOCIO3 and HOIO3 prepared from catalytic oxidation with halate
• oxyanion and salt of halogen
- form 4 type: hypochlorous acid, chlorous acid, chloric acid, perchloric acid
1. hypochlorous acid (+1)
- only CIO- ions and its salt
- prepared by electrolysis of cold brine or react CaO with chlorine
2. Halite ion(+3)
- only NaClO2 important
- preparation: react ClO2 with NaOH and H2O2
3. Halate ion (+5)
- prepared by electrolysis of hot brine
- usage: NaClO3 ( bleaching agent), KClO3( fireworks) iodate ( primary standard solution for the determination of iodide)
4. Perhalate ions (+7)
- potassium and ammonium salts produce by methasesis with sodium perchlorate
- usage: utilize in fireworks

SYAZIEMAH BINTI JASMANI

2021-01-14 04:35:40 UTC

Thankyou Dr for your explanation.
Summary Group VIIA:
Down the group :
-reactivity increases
-melting & boiling point increases
-the strength of Van der Waals increases

FLOURINE
- highest electronegativity then isoelectronic with noble gas
- preparation: electrolysis of HF dissolve in molten KF
- application : used as fluorinating agent for organic compounds

CHLORINE
-preparation :
i) electrolysis of molten NaCl in Down cell
ii) electrolysis of brine in Kellner-Solvay or Chor-alkali cell
iii) oxidation conc. HCl with MnO2@KMnO4
-application : in manufacture organic & inorganic,paper,water treatment, cleaning and bleaching

BROMINE
-preparation :
i) reacting of halide ion with stronger oxidizing agent
ii) reaction of metal halide with stronger oxidizing agent

Test To Identify Halide ions
-add conc. H2SO4 and heat
-add AgNO3 followed by NH3
-add Cl2@acidic NaClO then CCl4

Compounds of Halogen
1. Hydrogen Halides
-prepration : manufacture industrially by reaction of fluorspar,CaF2 with H2SO4
- preparation for HCl,HBr,HI :
i) reaction of halide salt with conc. H2SO4
ii) reaction of H3PO4 with halide salt
2. Oxoacid
-hypohalous acid,HOX (oxi. no : +1)
-halous acid,HOXO (oxi. no : +3)
-halic acid,HOXO2 (oxi. no : +5)
-perhalic acid,HOXO3 (oxi. no : +7)
-strength acidity :
HOXO3>HOXO2>HOXO>HOX
3. Oxyanion
-NaOCl (bleaching solution)
-mixture of solid CaCl2 & Ca(ClO)2 (bleachinng powder)
-Uses :
i) NaClO3 used as bleaching agent and herbicide
ii) KClO3 as primary oxidant in fireworks and a source of obtain O2
iii) Iodates as source for production of iodine
iv) potassium iodate as primary standard solution for determination iodide

HEMLYN HENDRY

2021-01-14 04:40:03 UTC

Summary of Group VIIA
-Founded as salts of halide ion because of their high reactivity.
Physicochemical Properties
-Has 7 valence electrons
-Going down the group,(m.p, b.p, size of molecules, strength of van der Waals force) increases
Fluorine
1)Has highest electronegativity of all elements
2)Preparation
-Electrolysis of HF in dissolved in molten KF
Chlorine
1)Preparation
-Electrolysis of molten NaCl in Down Cell
-Electrolysis of Kellner-Solvay using Chlor-alkali method
Bromine
1)Preparation
-Extraction by passing chlorine gas into chlorine gas into concentrated sea water
-Reacting a solution with substance that stronger oxidizing agent
-Reaction of metal halide with strong oxidizing agent
Application of elemental halogen
-Fluorine-fluorinating agent
-Chlorine-manufacture of organic and inorganic chemicals, water treatment
-Bromine-utilized in the manufacture of organic chemicals
Chemical Properties
-It undergoes displacement reactions, reaction with (water, alkali, metallic elements, metals)
Compound of Halogens
*Halides*
HF- prepared industrially by reaction of fluorspar
-Application-Manufacture of AlF3,BF3,pickling stainless steel
HCl-Prepared industrially by direct reaction of hydrogen and halogen
Application-Pickling of metals, acid treatment of oil and gas wells
-Physical properties of HX are such as thermal stability decreases, acid strength increases.
-Chemical Properties such as reacts with hydrogen, glass and reducing agents
Oxoacids
-4 types with general formula of
*HXO (+1)
Preparation :Disproportionation reaction
*HOXO (+3)
Preparation: Reaction of chlorine dioxide with hydrogen peroxide
*HOXO2 (+5)
Preparation: Reaction of iodine with nitric acid
*HOXO3 (+7)
Preparation: Catalytic oxidation followed by addition of strong acid
- If number of oxygen increases, oxidation number and acidity strength increases
Uses
NaClO3- bleaching agent for paper pulp, defoliant and herbicide
KClO3- primary oxidants in fireworks and matches, source obtaining oxygen gas in lab experiment
-IO3- Source of production of iodides
-Potassium iodate as primary standard solution for the determination of iodide

Thank you for the lecture dr!

ROSE SYAZWANI BT RAMLI

2021-01-14 04:51:53 UTC

Summary group VIIA

-Found as salts of the halide ion because high reactivity
-electronegativity decrease down the group
-has 7 valence electron
-down goup;
`increase m.p. and b.p. cause by van der Waals forces
`size of molecule increase,van der waals forces increase
-F has 1 oxidation number as it has highest electronegativity and only need 1 more electron to fulfil octet
-F high electronegativity so it can easily attract electron from nearby atom and F is then isoelectronic with noble gas.

INDUSTRIAL PREPARATION
-F obtain by electrolysis of HF dissolved in molten KF
-Cl;
a)electrolysis of molten NaCl in Down Cell
b) electrolysis of brine in Kellner-Solvay method or using Chlor-alkali cell
-Br;
`extract by passing chlorine gas into concentrated sea water.The bromide ion is oxidized to molecular bromine.
` Then, air is passed through the seawater to vapourise
bromine and transfer the gas into sulfite, SO32- solution.
`The sulfite will reduce bromine to bromide ion and chlorine gas is used to oxidize the bromide ion back to molecular bromine before distilling the pure bromine out

LABORATORY PREPARATION
-reacting a solution of the halide ions with any substance that is a stronger oxidizing agent
-Reaction of metal halide, MX, with strong oxidizing agent such as MnO2 in the presence of acid
-Chlorine can also be made by oxidation of concentrated HCl with MnO2 or KMnO4
-solution of Cl2 in water is readily obtained by reacting bleaching powder, CaCl2.Ca(ClO)2 or bleaching solution, NaOCl with HCl

CHEMICAL PROPERTIES
-halogen as oxidizing agent
`displacement reaction
`reaction wih H2S
REACTION OF WATER
-except F,the halogen react with water in disproportionation reaction

COMPOUND OF HALOGEN

1.hydrogen halides (HX)
`industrial preparation HF;
manufactured industrially by the reaction of fluorspa with sulfuric acid
`lab preparation HX;
`reaction of halide salts with conc.sulfuric acid except for HBr and HI because some hydride oxidized by acid
`physical property down the group;
-thermal stability decrease
-acid strengh increase
-HF weak acid as Fhas high electronegativity and didnt let go H easily
`chemical property;
-react with metals above hydrogen in electrochemical series,with oxides,hydroxide and carbonates
-HF react with glass
-HX as reducing agent

2.OXOACID
-Cl, Br and I form 4 types of oxoacid
-Fluorine form only one (hypoflurous acid, HOF)
because of its extreme difficulty to oxidize it.
*hypohalous acid,HOX (o.n:+1)
-disproportion reaction
*halous acid,HOXO(o.n:+3)
*halic acid,HOXO2 (o.n:+5)
*perhalic acid,HOXO3 (o.n:+7)
*strength acidity;
HOCL
3.OXYANION
*hypochlorous acid,ClO-
(o.n:+1)
*chlorous acid,ClO2-(o.n:+3)
*chloric acid,ClO3-
(o.n:+5)
*perchloric acid,ClO4-
(o.n:+7)

thank you dr!

WOO JOO LEONG

2021-01-14 04:51:57 UTC

Thank you dr for the class today, here is my summary on Group VIIA:

-Halogen found as salts of the halide ion because of their high reactivity

- They can have various oxidation state except F only has -1 due to the high EN

- Preparation of halogen, and difference between the down cell and the kellner-solvay process

- Application of halogen and reaction with water undergo disproportionation reaction (exception of fluorine)

- reaction with alkali solution, non metallic elements, and metals

- Test to identify halide ions

Compound of Halogen:
-preparation and applications of HX
- Physical properties of HX: acidity increase down the group except HF is the weak acid due to high EN difference
-Chemical properties: reacts with metal above H in the electrochemical series

Oxoacid of halogen
-HXO, HOXO, HOXO2, HOXO3
-HOXO3 is the strongest acid
-preparation of oxoacid
- effect of the number of oxygen on the acidity of oxoacids
-compounds of halogen contain oxyanion and salts of halogen
- uses

NUR HANISAH BT AZMAN

2021-01-14 05:14:57 UTC

Summary of Group VIIA

Known as halogen

Physichochemical properties

· Each atom has 7 e valence

· As go down the group:

-increase in melting point

-increase in boiling point which cause from increasing van der Waals forces

-size of molecule increase

-increase in van der Waals forces

Industrial preparation

· Fluorine obtained by electrolysis of HF

· Chlorine obtained by electrolysis of molten NaCl @ electrolysis of brine in kellner-solvay method or using Chlor-alkali cell.

· Bromine obtained by passing chlorine gas into concentrated sea water. The bromine ion is oxidized to molecular bromine.

Laboratory preparation

· Reacting the solution of the halide ions with any substance that is stronger oxidizing agent

· Reaction of metal halide with strong oxidizing agent such as MnO2 in presence of acid

· Chlorine can also be made by oxidation of concentrated HCL with MnO2 or KMnO4

· A solution of Cl2 in water is readily obtained by reacting bleaching powder or bleaching solution with HCL

Application

· Fluorine

-used as fluorinating agent

· Chlorine

-in the manufacture of organic and inorganic chemicals

-in water treatment

-in cleaning and sanitation

· Bromine

-mainly utilized in the manufacture of organic chemical

Chemical properties

· halogen as oxidizing agent

· Element that is more reactive can displace element that low reactive

Compound of halogen

· Hydrogen halide

ü HF

(Industrial process)

-reaction of fluorspar (acidspar), CaF2 with sulphuric acid

(Application of HF)

-glass etching and polishing

-semiconductor manufacture

In the manufacture of fluorohalogen hydrocarbons

ü HCL, HBr, HI

(industrial process)

-are manufactured by direct reaction of hydrogen and halogen

(Application of HF)

-acid treatment of oil and gas

-hydrolysis of protein and carbohydrates

-manufacture of CIO2

ü Physical properties

-thermal stability : HF>HCL>HBr>HI

-acid strength : HF<

ü Chemical properties

-reacts with metal above hydrogen in the electrochemical series

-react with metal oxides, hydroxides, and carbonates

-HF react with glass

-HX as reducing agent

· Oxoacid of halogen

ü Has 4 types

-perhalic acid +7

-halic acid +5

-halous acid +3

-hypohalous acid +1

ü Preparation of Hypohalous Acid

-disproportionation reaction

ü Preparation of halous Acid

-prepared by reaction of chlorine dioxide

ü Preparation of Halic Acid

-prepared by reaction of iodine with nitric acid

ü Preparation of Hypohalous Acid

-can be prepared from the catalytic oxidation of corresponding halite followed by addition of a strong acid

· Oxyanion and salts of halogen

ü Has 4 types

-hypochlorous acid

-chlorous acid

-chloric acid

Perchloric acid

ü Uses

-NaCIO3 is converted to CIO2 which is used as bleaching agent for paper pulp

-NaCIO3 as defoliant and herbicide

-KCIO3 as a source of obtaining oxygen gas in laboratory experiment

Perhalate ion and its salt

-sodium, ammonium perchlorates and potassium re particularly important industrially

-sodium perchlorate is manufactured from sodium chlorate (+5) by electrochemical synthesis

-potassium and ammonium salt are produced by metathesis with sodium perchlorate

-perchlorates are mainly utilized in fireworks.

-Ammonium perchlorate is exclusively used as oxidation agent in rocket

IFFAH IZZATI BINTI AZMAN

2021-01-14 05:24:12 UTC

Summary group VIIA

- has 7 valence electrons
- down the group:
i) melting point increase
ii) boiling point increase
iii) reactivity increase
iv) strength of van der waals forces increase

Fluorine
1) preparation
- electrolysis of HF in dissolved on molten KF
Chlorine
1) preparation
- electrolysis of molten NaCl in down cell
- electrolysis of Kellner- Solvay using Chlor-alkali method
Bromine
1) preparation
- extraction by passing Cl2 into concentrated sea water
- reacting a solution with substance that stronger oxidizing agent
- reaction of metal halide with strong oxidizing agent

Compound of Halogen
Halide,
- hypohalous acid, HOX
- halous acid, HOXO
- halic acid, HOXO2
- perhalic acid, HOXO3
- the number of lone oxygen attached to the same central atom affects the acidity of the oxacid
- the number of lone oxygen increases, the oxacid become a better proton donor

Oxyanion and salts of halogen
- -ite( oxidation number +1,+3)
- -ate( oxidation number +5,+7)
- hypo- lowest oxidation number
- per- highest oxidation number

Hypochlorite ion (ClO-)
1) preparation
- electrolysis of cold brine
- reaction of CaO or Ca(OH)2 with chlorine
2) uses
- as bleaching agent
- oxidizing agent
- disinfeectants

Halite ion (+3) and its salts
- only NaClO2 is industrially important
- salts are produced by reaction of ClO2 with NaOH and H2O2
- used as bleaching and oxidizing agent, deodorizing agent of odorous industrial emission

Halate ion (+5) and its salts
1) preparation
- electrolysis of hot brine

SYED MUHAMMAD KHAIRI BIN SYED NORDIN

2021-01-14 05:35:11 UTC

Summary group VIIA
found as salts of halide ion
down the group:
-increase in melting and boiling point
-increase in size
-increase strength in Van der Waals force

1)Fluorine
-highest electronegativity
-easily remove electron from nearby atom

-obtained by electrolysis of HF dissolved in molten KF
2)Chlorine
-obtained by electrolysis of molten NaCl in Down Process or electrolysis of brine in Kelner-Solvay Process
3)Bromine
-passing Cl2 gas into sea water
Application
Fluorine -fluorinating agent for organic compound
Chlorine- cleaning and sanitation
Bromine- fuel additive

Hydrogen Halide
HF
CaF2 + 2HwSO4 ->2HF +Ca(HSO4)2 with temperature of 200-350 C
HCl, HBr, HI = direct reaction with hydrogen

Oxoacid
-Hypohalous acid ,HOX (+1)
-Halous acid, HOXO (+3)
-Halic acid, HOXO2 (+5)
-Perhalic acid, HOXO3 (+7)

Oxoanion and salts of halogen
-Hypohalite ion (+1)
-Halite ion (+3)
-Halate ion (+5)
-Perhalate ion (+7)

SAHIZANZAIHAN BIN ISMAIL

sahizanzaihan114 — 2021-01-14 05:57:18 UTC

Thank you for today's lecture dr. here is my summary.

SUMMARY GROUP VIIA

Natural Occurance :

- fluorine - CaF₂(fluorspar)

- chlorine - NaCl (rock salt)

- Bromine (ocean)

- Iodine (Natrium iodate)

Physicochemical Properties

- has 7 valence electron, need 1 more electron to achieve noble gas

- down the group, melting and boiling point increase, size of molecules increase,

Van der waals forces increase

Why F has 1 oxidation state ?

- has high electronegativity, can easily remove electron from nearby atom, isoelectronic with noble gas

Preparation (industrial)

- F - electrolysis of HF dissolved in molten KF

- Cl - electrolysis of molten NaCl in down cell

- electrolysis of Brine in Kellner-solvay method

- Br - extracted by passing Cl gas into concentrated sea water

Preparation (lab)

- reacting a solution of halide ion with any substances that a stronger oxidizing agent

- reacting metal halide with strong oxidizing agent in the presence of acid

- oxidation of concentrated HCl in HNO₂ or KMnO₄ for Cl

- reacting bleaching powder with HCl for Cl

Application

- F - used as fluorinating agent, used in polymers, refrigerant fused

- Cl - manufacture of organic and inorganic chemicals, water treatment, cleaning and sanitaring

- Br - fuel additives, flame retardant

Chemical properties

- as oxidizing agent

- due to high electronegativity, the ability as oxidizing agent decrease down the group

- reaction with H₂S

- Reaction With Water

- halogen reacts with water in a disproportionantion reaction

- an element undergo both oxidation and reduction to form 2 different product

- also undergo disproportionation with alkali

- aqueous solution of non metal halides undergo hydrolysis except CCl₄

COMPOUND OF HALOGEN

- Hydrogen Halides

Preparation

- HF - reaction of fluorspar with sulfuric acid

Application

- in manufacture of aluminium fluoride, manufacture of fluorohalogen hydrocarbon, pickling stainless steel

Preparation

- HX - direct reaction of hydrogen and halogen

Uses

- pickling of metal, acid treatment of oil, neutralization

Lab Preparation

- reaction of halide salts with concentrated sulfuric acid

- not suitable for HBr and HI

- use poor oxidizing agent with halide salts

Properties

- thermal stability decrease down the group, acid strength increase

- why HF is a weak acid ? due to the bond of H and F are very strong, need more energy to break the bond, donating H+ is low

- react with metals above hydrogen in electrochemical series

- HF reacts with glass, HX as reducing agent

Oxoacid

- Cl, Br, I form 4 types of oxoacid

- F form only one (HOF) because its extreme to be oxidized

A) Hyperhalous acid (HOX)

Preparation

- hydrolysis of halogen, disproportionation reaction

Properties

- HOX are weak acid

- as oxidizing agent

industrial preparation of HOCl

- hydrolysis of dichlorine oxide

B) Halous acid (HOXO)

- chlorous acid is more stable than bromous and iodous acid

- prepared by reacting chlorine dioxide with hydrogen peroxide

C) Halic acid (HOXO2)

- only iodic acid can be prepared and isolated from its aqueous solution. Prepared by reacting iodine with nitric acid

D) Perhalic acid (HOXO3)

- perchloric and periodic acid can be prepared from catalytic oxidation

- strong and powerful oxidizing agent

- evaporation of aqueous solution of periodic acid give crystal of orthoperiodic acid

Effect of Oxygen in Oxoacid

- lone oxygen increase, the oxoacid become a better proton donor, easier to lost H+, acidity increase

Oxyanion and Salts of Hydrogen

A) Hypochloric ion

Preparation

- electrolysis of cold brine

- chlorine produced at anode mixed with hydroxide ion at cathode

- reaction of CaO/Ca(OH)₂ with Cl

- CaCl₂ + Ca(ClO)₂ is a bleaching powder

- hypohalite ion will undergo disproportionate reaction

B) Halite ion

- sodium chlorite is industrially important

- the salt used as bleaching and oxidizing agent, deodorizing agent of odorous industrial emission

C) Halate ion

Preparation

- electrolysis of hot brine

Uses

- NaClO₃ as bleaching agent, defoliant and herbicide

- KClO₃ as primary oxidant in firework and matches

- iodates as source of production of iodine

AISYAH BINTI MASHURE

aisyahm1 — 2021-01-14 06:00:34 UTC

Thank you Dr for the lesson

Halogen Group VII
🔴 Found as salt of halide ion bcs High reactivity
🔴 Physicochemical properties
-7 electron valence .neeed 1 electron to achive noble gas
-Down group :melting point and boiling point increase bcs
Van der Waals (LDF ) increase
Size of molecules increase down gp
🔴FlOURINE the highest electronegativity
Bcs Easily remove electron from other atom
-Fourine isoelectronic with noble gases
-Industrial prepare by Electrolysisi HF dissolved in molten KF (F2 obatined in anode)

🔴INDUSTRIAL PREPARATION
⚪FLORINE
-Industrial prepare by Electrolysisi HF dissolved in molten KF (F2 obatined in anode)
⚪CHLORINE
a)Electrolysis of molten NaCl in Down Cell
using molten NaCl(l),Na metal obtained in cathode,high temp
b)Electrolysis in Kellner-Solvay method
using Brine ,H2 NaOH obtained,normal Temp
⚪ BROMINE
Cl2(g)+2Br(aq)->2Cl-(aq)+Br2(g)
Air passed through seawater to vaporize Br and transfer gas into SO3 2-
SO3 2-+Br2->SO4 2-+2Br-
Chlorine gas oxidize Br-
Distill process to form pure Br

🔴LABORATORY PREPARATION
⚪ React halide ion with stronger oxidizing agent
⚪React metal halide,MX with strong oxidizing agent M:Na,K X:Cl,Br,I
⚪For chlorine ,Oxidation of HCl(concent) with MnO2/MnO4
⚪Solution Cl2 in water by CaCl2.Ca(ClO)2/NaOCl with HCl

🔴CHEMICAL PROPERTIES
HALOGEN IS OXIDIZING AGENT (reduction process) bcs HIGH ELECTRONEGATIVITY

⚪DISPLACEMENT REACTION
Ability halogen as oxidizing agent decrease down gp
⚪REACTION WITH H2S
X2+H2S->2HX+S
⚪REACTION WITH WATER EXC F
Disproportion reaction (type of redox)
•element undergoes oxidation and reduction form two different product
•halogen as oxidizing and reducing agent
•F2 & Cl2 can oxidize in water BASED Esrp
•30% s HOCl product and can decompose
⚪ REACTION WITH ALKALI SOLUTION
Disproportion reaction X=Cl,Br,I with OH- form X-,XO-,H2O
XO- disproportionate further -> X- + XO3 -
⚪REACTION WITH NON METALLIC ELEMENT
Non metal halides (aq)undergo hydrolysis exc CCl4 because doesn not have d orbital
⚪ REACTION WITH METAL
•F most reactive
•BeX2 and MgX2 have some covalent character
•Halides d&p block metals in low oxidation is ionic
•Halides d&p block in high oxidation state show some covalent

🔴 TEST for halides Cl,Br ,I (3 method)

🔴COMPOUND OF HALOGEN

1)HALIDE = Hydrogen Halides(HX)

•Industrial preparation
HF:
CaF2(s)+2H2SO4-->
HF(g)+Ca(HSO4)2 (200-350 c)
HCl,HBr,HI :direct hydrogen and halide

•Laboratory Preparation
- X:Cl,Br,I
NaX+H2SO4->Na2SO4+2HX
(not suitable for HBr & HI, some hydride oxidize by acid. then add excess H2SO4)
-X:Cl,Br,I (most suitable)
KX+H3PO ->K3PO4+3HX with P2O5

•Physical Properties
-Thermal Stability HX decrease down group
-Acid Strength HX increase down group
-HF weak acid: bond in H-F very strong ,very high electrongativity
F hard to let hydrogen go easily,need more energy to break bond
Extent in donating H+ is low

•Chemical properties
-React with above hydrogen in electrochemical series ,metal oxides ,hydroxides,carbonates
-HF react w glass
-HX as reducing agent

2)OXOACID HALOGEN

•Cl,Br,I four type oxoacid
1) Perhalic acid HOXO3 (+7) : Stong acid
2)halic acid HOXO2(+5)
3)halous acid HOXO (+3)
4) hypohlous acid HOX(+1)
•F only one hypoflourous acid HOF

•EFFECT NO OXYGEN IN ACIDITY
Lone pair oxygen increase,oxoacid better proton donor

Acid strength HOCl-Oxygen very electrogativee,
-draw electron ,
-more polar at OH ,
-easier to lose its H+

3)OXYANION ANS SALT HYDROGEN
1.Hypochlorite ion +1 ClO-
-Electrolysis cold brine ,Cl2 obtained in anode
-Cl2+NaOH-->NaOCl which solution
-if solution hot ,give NaCl +NaClO3 (bleaching solution)
2.Chloraite ion +3 ClO2 –
-CaO/Ca(OH)2 with Cl form Ca(OCl)2
-Mix Cacl2 and Ca(OCl)2 bleaching powder
3.Chlorate ion +5 ClO3 –
ClO2 + 2NaOH  2NaClO2+2H2O2+O2
ClO3 - + ClO- ClO2-
4.Perchlorate ion +7 ClO4 –
-Electrolysis of hot (70 c) brine
-Oxidation halide ion by hypochlorite ion (+3)
(for bromate and iodide salt )

Siti Hadijah binti Muslimun

2021-01-14 06:16:26 UTC

Thank you Dr for the explanation. Summary for group VIIA:

- Found as salts of the halide ion because of their high reactivity

- As we go down a group, increase in m.p & b.p caused by increase in van der Waals forces, increase in size of molecules and decrease in reactivity

- F only has 1 oxidation state due to F has the highest electronegativity and it can easily remove an electron from nearby atom.

- Reaction with water -disproportionation reaction except F

- Test to identify halide ions -add conc.H2SO4, add AgNO3 followed by NH3 and add Cl2 @ acidic NaClO -> CCl4

Fluorine

-Preparation -electrolysis of HF dissolved in molten KF

-Application -fluorinating agent for organic compounds

Chlorine

-Preparation -electrolysis of molten NaCl in Downs Cell & electrolysis of brine in Kellner-Solvay method or using Chlor-alkali cell

-Application -in paper and pulp industry, water treatment and cleaning & sanitation

Bromine

-Preparation -extracted by passing chlorine gas into concentrated sea water

-Application -mainly utilized in the manufacture of organic chemicals

Compound of Halogen

-Hydrogen Halide - preparation= manufacture industrially by reaction of fluorspar, CaF2 with H2SO4

-HX (Cl, Br, I) -reaction of halide salts with conc.H2SO4 & reaction of H3PO4 with halide salts
-strength acidity- HF << HCl < HBr < HI

- Oxoacid – Cl, Br & I form 4 types of oxoacid

- HOXO3 (+7) -Perhalic acid
- HOXO2 (+5) -Halic Acid

- HOXO (+3) -Halous Acid

- HXO (+1) -Hypohalous Acid

- Effect oxygen on the acidity of oxoacids- the num of lone oxygens increases, oxoacid -> better proton donor

- HOCl < HOClO < HOClO2 < HOClO3 (due to O very electronegative element & strong tendency to pull electron density away from any atom) - strength acidity

- Oxyanion – ite (+1, +3) & - ate (+5, +7)
- Uses – NaClO3 converted to ClO2 (uses as bleaching agent for paper clup) & as defoliant & herbicide

-KClO3 as primary oxidant in fireworks & source of obtaining oxygen gas in lab

-IO3- as source of production of I

-Potassium iodate as primary standard solution for the determination of iodide

SITI MASYITHAH BINTI MOHAMAD JAN

2021-01-14 06:52:02 UTC

Thank you dr for your well explaination. Here are my summary for Group VIIA which is halogen:
- 7 valence e
- high reactivity
- found as salts of the halide ion
- F has 1 oxi. state because highest electronegativity
CHEMICAL PROPERTIES
# as oxidizing agent=high electronegativity
#displacement reaction
- oxi. agent & oxi. power decreases down the group
- F2 will oxidize Cl-, Br-,I- ions
- Cl2 will oxidize Br-, I- ions
- Br2 will oxidize I- ions
# reaction with H2S
-there have oxidation and reduction process
# reaction with water
- reacts with water in a disproportionation reaction exc. F
# reaction with alkali solution
# reactions with non-metallic elements
# reactions with metals
COMPOUNDS OF HALOGEN
# hydrogen halides
- HF manufactured by the reaction of fluorspar
- HX(Cl,Br,I) manufactured by direct reaction of H2 and halogen
- acid strength: HF<#oxoacid of halogen
- perhalic acid
- halic acid
- halous acid
- hypohalous acid
- Cl,Br and I form 4 types of oxoacid above but F form only one which is hypofluorous acid
FLUORINE
# obtained by electrolysis of HF in molten KF
# as fluorinating agent for organic compounds
# used in polymers, aerosol propellants
CHLORINE
# electrolysis of molten NaCl in Downs Cell
# electrolysis of brine in Kellner-Solvay or Chlor-alkali cell
# used in the manufacture and inorganic chemicals
# used in paper and pulp industry
# in water treatment and cleaning and sanitation
BROMINE
# extracted by passing Cl2 into conc. sea water
# reacting solution halide ion with any sustance stronger oxi. agent
# reaction metal halide with strong oxi. agent in presence of acid
# oxidation of conc. HCl with MnO2 or KMnO4
# manufacture of organic chemicals:
- fuel additives
- flame retardants
- plants protection agent

NAURAH AFNAN BITI KAMARUDIN

2021-01-14 08:06:04 UTC

Thank you dr for your explanation.Here my summary:
As we go down the group :
-increase in melting point and boiling point.
-increase in size,strength of van der waals.
-F only form(1)oxi.no(due to increase in electronegativity,can easily remove
INDUSTRIAL PREPARATION
-electrolysis of HF dissolve in molten KF
-electrolysis of molten NaCI in Down Cell.
-In labarotary:reaching bromide ion with chlorine
APPLICATION
i)F:use as fluorinating agent for organic compound
ii)CI:cleaning and sanitation
iii)fire extinguishing
CHEMICAL PROPERTIES
-oxidizing agent(high electronegativity,tend to gain electrone)
-displacement reaction
-react with H20(redox reaction undergo both oxidation and reduction to form different product
-react with alkali,reaction with metal(halide of s block metal are ionic)
-reaction with non-metallic(form covalent bond)
HYDRIDE
-HF: manufactured industrially by reaction of fluorspar,CaF2 with H2SO4 at 200-350C
-glass etching and polishing
OXOACID
preparation
-hypohalous acid (HOX)+1---(weak acid ,oxidizing agent
-halous acid(HOXO)+3---(more stable than HOBrO and HOIO)
-halic acid (HOXO2)+5
-perhalic acid (HOXO3)+7-----(strong acid,powerful oxidizing agent)
OXYANION
i)HYPOCHLORITE ION (+1)
-electrolysis of cold brine,NaOCI called bleaching solution
ii)HALITE ION (+3)
-NaCIO2(bleaching,oxidizing agent)
-HALATE ION(+5)
-electrolysis hot brine

SITI AINA AISHAH BINTI AZIZAN

2021-01-14 08:25:41 UTC

Thank you dr for today class :)
Here is the summary of Group VIIA:

Halogen

- found as salt in halide ion (high reactivity)
- oxidation number up to +7 except F, only -1 due to higher EN
- down the group
: increase mp & bp ( bcs increase VDW forces )
: increase of size, increse strength of VDW forces
Industrial preparation:

Flourine

- by electrolysis of HF dissolved in molten KF
- KF as electrolyte : bcs pure HF is non-conducting molecular compound

Chlorine

a) Electrolysis of molten NaCl
- Na metal (cathode)
- high temp.
b) Electrolysis of brine in Kellner-Solvay method / using Chlor-alkali cell
- produce H2 gas and NaOH
- normal temp.

Bromine

Laboratory preparation:
1) Reacting a solution of the halide ions with any substance that is a stronger oxidizing agent
2) Reaction of metal halide with strong oxidizing agent (presence of acid)
3) Chlorine can also be made by oxidation of concentrated HCl with MnO2/KMnO4
4) Solution of Cl2 in water readily obtainde by reacting bleaching powder/solution with HCl
Applications halogen

Fluorine

- as fluorinating agent

Chlorine

- manufacture in organic and inorganic chemicals
- water treatment

Bromine

- utilized in the manufacture of organic chemicals
Test identify halides ion
1) Add conc. H2SO4 and heat
2) Add AgNO3(aq) followed by NH3(aq)
3) Add Cl2(aq)/acidic NaClO(aq) and then CCl4(l)

Compounds of halogen
Hydrogen halides (HX)
Industrial preparation
1) HF
- reaction of fluorspar, CaF2 with sulfuric acid at 200-300 degree celcius
2) HCl, HBr, HI
- direct reaction of hydrogen and halogen
Laboratory preparation:
1) Halide salts + conc. H2SO4
( not suitbale for HBr and HI )
2) phosphoric acid + halide salts, presence of P2O5
( more suitable prepare HX )
Down the group:
- Thermal stability decrease
- Acid strength increase
Chemical properties:
- react with metal above hydrogen
- reacts with metal oxides, hydroxides, carbonates
- HF + SiO2 (glass)
- HX reducing agent
- strength as reducing agent, increase down the group

Oxoacid
- Hypohalous acid, HOX
(oxi. no. = +1)
- Halous acid, HOXO
(oxi. no. = +3)
- Halic acid, HOXO2
(oxi. no. = +5)
- Perhalic acid, HOXO3
(oxi. no. = +7)
- Strength acidity:
HOXO3 > HOXO2 > HOXO > HOX

Oxyanion
: Hypo- (Lowest oxi. no.)
: Per- (Highest oxi. no.)
- Hypochlorite ion (+1)
Preparation salt:
1) Electrolysis of cold brine (Chlor-alkali industry)
2) Reaction of CaO/Ca(OH)2 with chlorine
- Halite ion (+3)
Preparation salt:
1) ClO2 + NaOH and H2O2
- Salts used as bleaching and oxidizing agent
- Halate ion (+5)
Preparation:
1) Electrolysis of hot brine
2) Oxidation of halide ion -1 by hypochlorite ion +1 (for preparation bromate and iodate salt)
Uses:
- NaClO3 --> ClO2, as bleaching agent for paper pulp
- NaClO3 as defoliant and herbicide
- KClO3 source of obtaining oxygen gas in lab experiment
- Perhalate ions
: Sodium perchlorate from sodium chlorate (+5) by electrochemical synthesis
: Potassium and ammonium salts by metathesis with sodiu perchlorate
- Perchlorate utilized in firewoks

SITI RAIHANAH BINTI ROSLAN

2021-01-14 08:30:28 UTC

HALOGEN

can found as salts of the halide ion (high reactivity)
the most electronegativity group compared to others.
variety oxidation state except F 1 oxidaation state only (highest electronegativity, can easily removed from nearby atom)
form singly bonded diatomic molecules
increase in melting & boiling point (van der Waals forces)
size of molecules

preparation

industrial
Fluorine : electrolysis of HF dissolved in molten KF
Chlorine : elecyrolysis of molten NaCl in Downs Cell & electrolysis in brine in Kellner-Solvay/Chlor-alkali cell
Bromine : extracted by passing chlorine gas into concentrated sea water

laboratory

reacting a solution of halide ion with stronger oxidizing agent
reaction of metal halide with strong oxidizing agent in presence of acid
chlorine made by oxidation of concentrated HCl with MnO2/KMNO4

chemical properties

oxidizing agent (displacement reaction & reaction with H2S)
reaction with water (dispropotionation)
reaction with alkali (dispropotionation)
reaction with non metal
reaction with metal

compounds of halogen
1. HYDROGEN HALIDE(HX)

reaction of fluorspar(acidspar),CaF2 with sulfuric acid

2. OXOACID OF HALOGEN

HOX (hypohalous acid)
HOXO (halous acid)
HOXO2 (halic acid)
HOXO3 (perhalic acid)
the no of lone oxygen increase, the oxoacid becomes a better proton donor

3. OXYANION AND SALTS OF HALOGEN

hypochlorite ion (+1)
halite ion (+3)
halate ion (+5)

thank you dr for today explanation :)

Zulfa Annisa binti Mohd Noor

zulfaa480 — 2021-01-14 08:52:09 UTC

Thank you for the lesson about Group VIIA . Here is my summary about Group VIIA :-

Can be found as salts and halide ion
Going down the group , electronegativity decreases while melting point , boiling point and strength of van der Waals forces increases
Oxidation number : -1 to +7 except for oxidation number of F : -1

Industrial Preparation
F: Electrolysis of HF dissolved in molten KF
Cl : -

Electrolysis of molten NaCl in Down Cell
Electrolysis of brine in Kellner- Solvay method/ Chlor-alkali cell

Br: Pass chlorine gas into concentrated sea water.
Laboratory Preparation

React a solution of the halide ions with any substance that is a stronger oxidizing agent
Reaction of metal halide with strong oxidizing agent in the presence of acid
Cl :

Oxidation of concentrated HCl with MnO2 or KMnO4.
Reaction with bleaching powder and bleaching solution with NaOCl with HCl.

Application

F: as fluorinating agent for organic compounds.
Cl : - Used in the manufactured of organic and inorganic chemicals , paper and paper industry to bleach the pigment , in water treatment and in cleaning and sanitation.
Chemical Properties
- As oxidizing agent.
- Form covalent bonds with non-metallic elements
Types of test to identify halide ions.

Add conc. H2SO4 and heat
Add AgNo3(aq), followed by NH3(aq)
Add Cl2(aq) or acidic NaClO(aq) and CCl4(l)

Compound of Halogen
Hydrogen Halides

HF :
Industrial preparation - By reaction of fluorspar (acidspar) , CaF2 with sulfuric acid at elevated temperature.
Application :
-Pickling stainless steel.
-Glass etching and polishing.
-Semiconductor manufacture.
HCl, HBr and HI :
Industrial preparation - Direct reaction of hydrogen and halogen.

Laboratory preparation: - Reaction of halide salts with concentrated sulfuric acid ( not suitable for preparation of HBr and HI because it will be oxidize by the acid. )
Reaction of phosphoric acid with halide salts in the presence of P205.

Uses of HCl acid : - Pickling of metals, acid treatment of oil and gas wells and neutralization in organic and inorganic chemistry.
Physical properties :-
-Thermal stability decreases while acid strength increase down the group.
Oxoacid
- Perhalic acid, HOXO3, (+7)
-Halic acid, HOXO2(+5)
-Halous acid , HOXO(+3)
-Hypohalous acid, HXO(+1)

Acid strength is depends on the number of lone oxygen attached to central atoms.

Oxyanion
-Hypochlorite ion , ClO- (+1)
-Chlorite ion , ClO2- (+3)
-Chlorate ion, ClO3- (+5)
-Perchlorate ion, ClO4-(+7)

SITI NAZURAH BINTI NAZARUDDIN

2021-01-14 10:04:19 UTC

Thank you Dr for the lesson. Summary for group VIIA:
-Ifound as salts of the halide ion due to the high reactivity of this group.
-increase in mp, bp, size of the molecule.
-F has the highest electronegativity and it can easily remove an e- from a nearby atom.
-F is then isoelectronic with a noble gas.
IMDUSTRIAL PREPARATION
-F obtained by an electrolysis of HF dissolved in molten KF.
-Cl : electrolysis of molten NaCl in Down Cell
- Cl: electrolysis of brine in Kellner-Solvay method or using Chlor-alkali cell.
LABORATORY PREPARATION
- Reacting a solution of the halide ions with any substance that is a stronger oxi agent.
- Reaction of metal halide, MX, with strong oxi agent
- Cl can also be made by oxidation of concentrated HCl with MnO2 or KMnO4
- Solution of Cl2 in H20 is readily obtained by reacting bleaching powder or bleaching solution.
CHEMICAL PROPERTIES
-Halogen as oxidizing agent (but is F rarely used).
REACTION WITH WATER
- with the exception of F, halogen reacts with water in a disproportionation reaction.
REACTION WITH ALKALI SOLN
- General disproportionation reaction for Cl,Br,I
REACTION WITH NON-METALLIC ELEMENT
-form covalent bonds
-Aq solution of non-metal halides undergo hydrolysis reaction.
TEST TO IDENTIFY HALIDE ION
- add conc.H2SO4 and heat
-add AgNO3(aq). followed by NH3(aq).
-add Cl2(aq) or acidic NaClO(aq) and then CCl4.
OXOACID OF HALOGEN
PREPARATION
-hypohalous acid,HOX : hydrolysis of halogen
-halous acid, HOXO: reaction of ClO2 with H2O2 in the presence of Barium.
-Halic Acid, HOXO2: reactin of iodine with nitric acid.
-Perhalic acid.HOXO3: from the catalytic oxidation of the corresponding halate, XO3- followed by the addition of a strong acid.
-the acid strength:
HOCl-Hyperchlorite ion(+1) and its salt.
-halite ion (+3) and its salts
-halate ion (+5) and its salts

LIANA FAQIHAH BINTI MOHD JAFFRI

2021-01-14 11:50:17 UTC

Summary group VIIA
-Each atom has 7 valence electron and need 1 electron to achieve noble gas configuration
-Down the group , melting and boiling point increases
-caused by increased in vander waals forces
WHY F ONLY HAVE 1 OXIDATION STATE
-Fluorine has highest electronegativity , so it can easily removed electron .
-Fluorine then isoelectronic with noble gases
-Fluorine obtained by electrolysis of HF dissolved in molten KF
-Pure HF is nonconducting
-Application ; As fluorinating agent
CHLORINE
-Preparation ; electrolysis of molten NaCl , Electrolysis of brine in Kellner-Solvay
-Application : manufacture of organic and inorganic chemical
BROMINE
-Preparation ;
1. Reacting solution of halide ion with substance having strong oxidizing agent
2. Reaction metal halide with strong oxidizing agent
3. Oxidation of concentrated HCl with MnO2 or KMnO4
4. Reacting bleaching powder with HCl
-Acid strength of HX :
HF<OXOACID HALOGEN
1. HXO ( Hypohalous acid) +1
2. HOXO ( Halous acid ) +3
3. HOXO2 (Halic acid) +5
4. HOXO3 (Perhalic acid ) +7
-Acid strength oxoacid chlorine
HOCl-Explanation : more lone oxygen they will have , they become more polar and tend to pull central atom ,Hence acid strength increases

OXYANION OF SALTS HYDROGEN
-HOCl Hypovhlorous acid (+1)
-HOClO Chlorous acid (+3)
-HOClO2Chloric acid (+5)
-HOClO3 Perchloric acid (+7)

Thankyou Dr .

Ch'ng Zi Long

2021-01-14 12:01:30 UTC

Summary of Group VIIA (halogen)
- 'hals': salt, 'gennan': generate
- combine with metals to from salts
- form diatomic molecule
- melting and boiling point increase.
- F has the highest electronegativity
- F and Cl are prepared by electrolysis
- Cl can either prepared by Downs cell or Kellner-Solvay method
- Br is prepared by using sea water as resource.
- both has its own preparation and and specific appplication

chemical properties

- as strong oxidizing agent
- react with H₂S
- react with H₂O (disproportionation reaction

Hydrogen halide

- thermal stability decrease down the group
- acid strength increase down the group
- HF reacts with glass (SiO₂)

Halide oxoacid

- has 4 types: hypohalous acid, halous acid, halic aicd and perhalic acid
- the more the no, of O attached to the central atom, the stronger the acid strength.

Halide oxyanion

- hypohalite ion (only ClO^- is important)
- halite ion (only NaClO₂ is important)
- halate ion
- perhalate ion
- uses: mainly used as bleaching agent and firework

IRDINA BINTI AZUWIR

irdina01 — 2021-01-14 12:25:36 UTC

Group VIIA
- Found as salts (high reactivity)
- Down the group: increase mp & bp, size, and strength of Van der Waals

Fluorine

- Has only 1 oxidation state (highest electronegativity)
- Ind. prep.: electrolysis of HF dissolved in molten KF (HF is non-conducting)

Chlorine

- Ind. prep.: electrolysis of molten NaCl, or brine in Kellner-Solvay method

Bromine

- Ind. prep.: passing chlorine gas into conc. sea water then seawater passed through vaporised bromine, finally chlorine gas oxidize bromide ion.

- Lab prep.:
1. react halide ions with stronger oxidizing agent
2. react MX with strong oxidizing agent in presence of acid
3. Cl2 can also by oxidation of conc. HCl with MnO₂ or KMnO₄
4. React bleaching powder / solution with HCl
- Application of elemental halogen
F: fluorinating agent
Cl: manufacture organic and inorganic prod., paper & pulp ind., water treatment, cleaning & sanitation
- Chem. Prop.:
Oxidizing agent: displacement reaction, reaction with H₂S
- Reaction with water: disproportionation reaction (oxi & red at the same time)
only F₂ & Cl₂ oxidize water (E°_srp)
- Reaction with alkali sol.:
disproportionates when X = Cl, Br, I
XO- tends to disproportionate further
- Reactions with non-metal:
forms covalent bonds
aq. sol. of non-metal halides undergo hydrolysis reaction
- Reacts with metals
- Tests to identify halide ions: add conc. H₂SO₄, add AgNO₃(aq) followed by NH₃(aq), add Cl₂(aq) then CCl₄(l)
Hydrogen Halides

- HF

Ind. Prep.: reaction of CaF₂ with H₂SO₄
App.: manufacture aluminium fluoride, boron trifluoride, uranium tetrafluoride & ammonium hydrogen fluoride, fluorohalogen hydrocarbons. pickling stainless steel. glass etching & polishing, semiconductor manufacture.

- HX (X = Cl, Br, I)

manufactured by direct reaction

HCl Uses: pickling of metals, acid treatment of oil & gas wells, neutralization, hydrolysis of protein & carb., regen of ion-exchangers, manufacture of ClO₂
Lab prep.: reaction of halide salts with H₂SO₄ (not suitable for HBr & HI), reaction of phosphoric acid with halide salts in the presence of P₂O₅
Phys. Prop.: Thermal stability decreases & acid strength increases down the group
Chem. Prop.: reacts with metals above H in electrochemical series, metal oxides, hydroxides & carbonates, HF reacts with glass, HX reducing agent

Oxoacid
- Cl, Br & I (4 forms) F (1 form, difficult to oxidize)
[hypo - lowest oxidation no., per - highest oxidation no.]

- Hypohalous acid (ON: +1)

Prep.: hydrolysis of halogen
HOX weak acids
oxidizing agents
Ind. Prep. of HOCl: hydrolysis of dichlorine oxide

- Halous acid (ON: +3)

HOClO most stable
HOClO prep.: react ClO₂ with H₂O₂ in presence of Ba(OH)₂ then Ba(ClO₂)₂ reacted with H₂SO₄

- Halic acid (ON = +5)

Only HOIO can be easily prepared by react I₂ with HNO₃

- Perhalic acid (ON = +7)

HOClO₃ & HOIO₃

Prep.: catalytic oxidation of XO₃^- followed by addition of strong acid.
Is a strong acid & powerful agent (oxidizes explosively)
Evaporation of HOIO_3(aq) gives crystals of H₅IO₆
Effect of no. of O on acidity:
Lone O increases, acidity increases
O is very electronegative = strong tendency to pull electron density away

Oxyanion & salts of halogen
[-ite for +1, +3 & -ate for +5, +7]

- Hypochlorite ions

Prep.: electrolysis of cold brine, react CaO or Ca(OH)₂ with Cl₂

[NaOCl(aq) is bleaching sol.
Mixture of CaCl₂ & Cs(ClO)₂ is bleaching powder]

Hypohalite ion in aqueous sol. undergo disproportionate reaction
Rate of reaction: ClO^- < BrO^- << IO^-
Hypochlorite salt used as bleaching agent, oxidizing agent & disinfectant

- Halite ions

Only NaClO2 important.

Salt uses: bleaching, oxidizing & deodorizing agent.
ClO3-(aq) + ClO-(aq) -> ClO2(aq) is possible under carefully controlled conditions

- Halate ions

Prep.: electrolysis of hot brine, oxidation of halide ion by hypochlorite ion (bromate & iodate salt)

Uses:-

NaClO₃ converted to ClO₂ to be bleaching agent, NaClO₃ as defoliant & herbicide,
KClO₃ as primary oxidant in fireworks & matches, and as source of obtaining O₂ gas
Iodates as source for prod. of iodine, potassium iodate as a primary standard sol. for determination of iodide

- Perhalate ions

Sodium, potassium & ammonium perchlorates are important
Sodium perchlorate manufactured from sodium chlorate by electrochemical synthesis
Potassium & ammonium salts prod. by metathesis with sodium perchlorate
Perchlorate are mainly utilized in fireworks. Ammonium perchlorates exclusively in rocket fuel

NURHANIS KHALIESAH BINTI MOHAMAD ZAMANI

2021-01-14 12:50:26 UTC

Thank you Dr for the lesson and this is my summary for Group VIIA.

- Found as salts of the halide ion because of their high reactivity
- Down the group, increase in melting point, boiling point, size of molecules
Fluorine
- Has only 1 oxidation state
- Has highest electronegativity
- Obtained by electrolysis of HF dissolved in molten KF
Chlorine
- Prepared by electrolysis of molten NaCl in Down Cell or brine in Kellner-Solvay method
Bromine
- Prepared by passing Cl gas into conc. sea water
Application
- F as fluorinating agent, Cl in water treatment and Br in fuel additives
Chemical properties
- As oxidizing agent
- React with H₂S
- React with H₂0
- React with alkali solution
- React with non metallic elements
- React with metals
Hydrogen Halide
- Properties: thermal stability decrease down the group, acid strength increase down the group
HF
- Prepared by the reaction of CaF₂ with H₂SO₄
- application: manufacture of AlF₃, BF₃
HCl
- Prepared by reaction of hydrogen and halogen
- Uses: pickling of metals
Oxoacid
1) Hypohalous acid (+1)
- Oxidizing agents
- Preparation of HOCl by hydrolysis of ClO₂
2) Halous acid (+3)
- HOClO prepared by reaction of ClO₂with H₂O₂ in the presence of Ba(OH)₂
3) Halic acid (+5)
- Ony HOIO2 can be prepared by reaction of I₂ and HNO₃
4) Perhalic acid (+7)
- HOClO₃ and HOIO₃ can be prepared from catalytic oxidation of the XO₃-followed by strong acid
Effect of the no of oxygen on acidity
- Number of lone oxygen increases, oxoacid becomes a better proton donor
Oxyanion
Hypohalite ion
- ClO- can be prepared by electrolysis of cold brine
- Hypohalite ion in aqueous solution undergo disproportionate reaction
- Hypoiodite ion doesn't exist in solution
Halite ion
- salts are used as bleaching and oxidizing agent
- Prepared by reaction of ClO_{2 with}NaOH
and H₂O₂Halate ion
- Prepared by electrolysis of hot brine
Uses
- NaClO₃ as defoliant and herbicide
- KClO₃ in fireworks
- Iodate as source for production of iodine

WAN NUR ANIS FAQIHAH BINTI WAN MAT

2021-01-14 13:28:24 UTC

Thank you for the explaination of halogen group and here is my summary.
-found as salts of halide ion due to their high reactivity
-as it goes down the group, the boiling point and melting point increase due to the increase in Van der Waals forces (Dispersion forces)
-F has highest electronegativity so it easily remove an electron from a nearby atom(one of the reasons why F only has 1 oxidation state)
FLOURINE
-F obtained by an electrolysis of HF dissolved in molten KF
-used as flourinating agent for organic compounds
CHLORINE
-Cl can be obtained industrially by electrolysis of molten NaCl in Down Cell and electrolysis of brine in Kellner-Solvay method or using Chlor-alkali cell ( Down Cell and Kellner-Solvay method has H2 gas at cathode) and by laboratory which oxidation of concentrated HCl with MnO4 and reacting bleaching powder or reacting bleaching solution with HCl
-one of the uses is in the manufacture of organic and inorganic chemical
BROMINE
-Br can be prepare by passing through Cl2 gas into concentrated sea water(industrially) and for laboratory can be prepare by reacting the Br ion with Cl and reaction of metal halide with concentrated sulfuric acid and strong oxidizing agent
CHEMICAL PROPERTIES
-oxidizing agent due to the high electronegativity compared to other elements as it tends to gain electron •displacement reaction, oxodizing power decrease as it goes down the group: F2>Cl2>Br2>I2)
•reaction with H2S
•reaction with water in a disproportionation reaction(redox reaction), the reactant (halogen) serve as oxidizing and reducing agent
•reaction with alkali solution(general disproportionation reaction for Cl, Br and I)
•reaction with non-metal form covalent bond (non-metal halides(aq) undergo hydrolysis reaction except CCl4 because C has no d orbital to receive a pair of electron from water molecule)
•reaction with metal
-halides of d and p block metal has two type of oxidation state (low and high)for high it will be ionic and low will show covalent character
-Halogen has their own test for each element in group
COMPOUND OF HALOGEN
1.Hydrogen Halides, HX(HF, HCl, HBr, HI)
-thermal stability decrease down the group
-acid strength increase down the group
-HF is a weak acid due to the high electronegativity difference so it doesnt let H go easily
-HX as reducing agent
-HF react with glass, SiO2
2.Oxoacid of Halogen
-Perhalic acid(+7), Halic acid(+5), Halous acid(+3), Hypohalous(+1)
-F only form hypoflorous acid because its extremely difficult to oxidize it.
-hypohalous acid, HOX can be prepare by hydrolysis of halogen (disproportionation reaction)
-Halous acid, HOXO can be prepare by reaction of ClO2 with H2O2 in the presence of Ba(OH)2 then the formation of precipitate of the reaction react with H2SO4
-Halic acid, HOXO2 can be prepare by reaction of iodine with HNO3(only for I)
-Perhalic acid, HOXO3 can be prepare from the catalytic oxidation of the corresponding halate followed by the addiction of a strong acid
-increase of lone oxygen attached to the central atom will incease acidity to become a better proton donor
3.Oxyanion and salts of Halogen
-ite(+1,+3)(low) and ate(+5,+7) (high)
-Hypohalite ion ( ClO3- is important which can be prepare by electrolysis of cold brine in Chlor-alkali industry and reaction of CaO or Ca(OH)2 with Cl2
-Halite ion (only NaClO2 is important which be can be prepare by reaction of ClO2 with NaOH and used as bleaching agent and oxidizing agent)
-Halate ion can be prepare by electrolysis of hot brine and used as bleaching agent for paper pulp, defoliant and herbicide
-Perhalate ion can manufacture from sodium chlorate by electrochemical synthesis(for Na)

PUTERI FARISAH BALQIS BINTI ERWAN

2021-01-14 13:30:29 UTC

Thank you dr for today lesson, this is my summary for group VIIA (halogen)

-occurrence : salts of the halide ion ( high reactivity)

-Has 7 electron valence , need only one electron to achieve noble gas cong.

-Down group, INCREASES in melting point, boiling point (Van der Waals force)
WHY F ONLY HAS 1 OXODATION STATE ?

-highest electronegativity
-easily remove an electron from nearby atom

-isoelectronic with nobe gas

INDUSTRIAL PREPARATION

Fluorine

-electrolysis of HF dissolve in molten KF(electrolyte)
Chlorine

-Electrolysis of molten NaCl in Downs Cell

-Electrolysis of brine in Kellner-Solvay method or using Chlor-alkali cell.

Bromine

-Extracted by passing chlorine gas into concentrated sea water.
APPLICATION
-fluorinating agent
-bleach
-water treatment
-cleaning sanitation
CHEMICAL PROPERTIES
Halogen Oxidizing agent
-high electronegativity
-displacement reaction
-reaction with H2S
expect flourine , react with water (disroprotian reaction)
COMPOUNDS OF HALOGEN
1)Hydrogen Halides (HX)
-HF
-Reaction of fluorspar at 200-300 c
-use in manufacture aluminum fluoride, boron trifluoride, uranium tetrafluoride., gas etching, polishing, semiconductor
-HCL
direct reaction with hydrogen and its halogen
WHY HF IS WEAK ACID ?
-bond fluorine and hydrogen very strong, high electronegativity.
not easy to break the bond/
2)OXOACID OF HALOGEN
-CL, BR, I ( 4 types of oxoacid )
-Fluorine (hypofluorous acid , HOF)
-More O( not O in OH) attached to central atom, higher acidity.
Increase lone oxygens increases, become proton donor.
HOCL3)OXYANION AND SALTS OF HALOGEN
-ending -ite (+1,+3) -ate (+5,+7)
-prefixes hypo- lowest
-per- highest oxidation no.

EMERALDISYAH ALIFIA WISAKSONO

wisaksono — 2021-01-14 13:58:47 UTC

Thank you for the explanation, below is my summary of Group VIIA;
- Halogen: Hals (salt) & Gennan (generate)
- Form single bonded diatomic molecules.
- Going down the group: m.p. and b.p. increases (increase in van der Waals forces), size increases.
- Properties: oxidizing agent, high electronegativity, disproportionation reaction with water, reaction with H2S, form covalent bonds with non-metallic elements, different reactions with metals

1. Fluorine
- F has the highest electronegativity of all the elements.
- Can easily remove an electron from nearby atom.
- Electronic with noble gas.
- Lab preparation: Electrolysis of HF dissolved in molten KF.
- Uses: Polymers, refrigerant fluids, aerosol propellants, & non-flammable anesthetics.

2. Chlorine
- Lab preparation: Electrolysis of molten NaCl in Downs Cell, Electrolysis of brine in Kellner-Solvay method, oxidation of conc. HCl with MnO2/KMnO4.
- Uses: Manufacture of organic & inorganic chemicals, bleaching agent for paper, water treatment, cleaning & sanitation.

3. Bromine
- Lab preparation: Reacting bromide ion with chlorine.
- Uses: Manufacture of organic chemicals.

4. Hydrogen halides
- HF: manufactured by reeaction of fluorspar with sulfuric acid, used in the manufacture of aluminum fluoride, glass etching & polishing, semiconductor manufacture.
- HCl, HBr, HI: manufactured by direct reaction of hydrogen and halogen, used in pickling of metals, acid treatment of oil and gas wells, regeneration of ion-exchangers, manufacture of ClO2.
- Thermal stability decreases and acidity increases down the group.
- Electrochemical series.

5. Oxoacid of Halogen
- Hypohalous acid, halous acid, halic acid, perhalic acid.
- Lone oxygen affects acidity, HOCl<<
6. Oxyanion and Salts of Halogen
- ite (+1 & +3) and ate (+5 & +7)
- Hypochlorite ion (ClO-) and its salts are important, prep is by electrolysis of cold brine.
- Halite ion (NaClO2) is important, prep by reaction of ClO2 with NaOH and H2O2.
- Halate ion, prep by electrolysis of hot brine.
- Uses: Bleaching agent for paper pulp, defoliant and herbicide, primary oxidant in fireworks and matches, obtaining gas in lab experiment, IO3- as a source of production of iodine.

SITI NOR SYAFIQAH BT MOHAMAD

2021-01-14 14:34:46 UTC

Thankyou Dr for the explaination of halogen group so this is my summary,

-has 7 valence electron
-can be found as salts of the halide ion as their high reactivity
-share electron with themselves to achieve octet rule
-down the group
>reactivity ⬇
>melting point ⬆
>boiling point ⬆
>size of molcule ⬆

FLUORINE 🥦
-only has 1 oxidation state
-highest electronegativity in PT
-IP:obtained by an electrolysis of HF(nonelectrolyte) dissolved in molten KF(as electrolyte)
-uses : polymers,refrigerant fluids,aerosol propellants,& non-flammable anethestics

CHLORINE🧀
-LP :
1-electrolysis of molten NaCl in down cell
2-electrolysis of brine in Kellner-Solvay method/using Chlor alkali cell
-uses : manufacture of organic & inorganic chemicals,bleaching agent for paper,water treatment,cleaning & sanitation

BROMINE🦋
-LP : reacting bromide ion with chlorine
-USES : manufacture of organic chemicals

HYDROGEN HALIDES
-HF ->manufactured by reaction of fluorspar with sulfuric acid
-HCl,HBr,HI ->manufactured by direct reaction of hydrogen adn halogen
-down the group,thermal stability ⬇ and acidity ⬆
-electrochemical series

OXOACID
-CI,Br,I form 4 types of oxoacid
-F form hypofluorous acid cs it extremely difficult oxidize it
-hypohalous acid (+1),halous acid (+3),halic acid (+5),perhalic acid (+7)
-lone oxygen affect the acidity of oxoacid
-HOCI
OXYANION & SALTS OF HALOGEN
-ite (+1 and +3 ) ,ate(+5 and +7)
-prep by electrolysis of cold brine(hypochlorite ion )
-prep by reaction of CIO2 with NaOH & H202(halite ion )
-prep by electrolysis of hot brine (halate ion )
-uses: bleaching agent for paper pulp,obtaining gas in lab experiment,

NURFATINI NASUHA BINTI MOHD NAIM

2021-01-14 14:40:41 UTC

Thank you so much for today lessons Dr. Here is my summary:

Natural occurrence

F - flourspar, cryolite, fluoroapatite

Cl - rock salt, sylvite, ocean, great salt lake

Br - ocean

I - ocean, natrium iodate with chile saltpetre

Down the group:

- Electronegativity decreases

- Oxi number : -1 -> +7 ( F : -1 only)

- Acid oxides

- F2 : colourless gas

- Cl2 : yellowish-green gas

- Br2 : reddish-brown liquid

- I2 : violet solid

- Boiling point and melting point increases

F only has -1 oxidation number

- F has highest electronegativity

- F can easily remove electron from nearby atom

- Isoelectronic with noble gas

Preparation Industrial:

- electrolysis of HF dissolved in molten KF

- electrolysis of molten NaCl in Downs Cell

- Electrolysis of brine in Kellner-Solvay method or Chlor-alkali cell

- pass Cl2 into conc. sea water, air pass through sea water, sulfite ion reduce bromine to bromide ion, Cl2 oxidize bromide ion back to bromine before distill pure bromine out

Preparation Laboratory:

1. React halide ions with stronger oxidizing agent

2. React metal halide with strong oxidizing agent

3. Cl made by oxidation of conc. HCl with MnO2 or KMnO4

4. React CaCl.Ca(ClO)2 or NaOCl with HCl

Application

- fluorinating agent for organic compound

- Polymer

- Refrigerant fluid

- Aerosol propellant

- Non flammable anaesthetic

- manufacture organic/inorganic chemical

- Bleach pigment

- Water treatment

- Cleaning, sanitation

- manufacture organic chemical

- Fuel additive

- Flame retardant

- Plants protection agent

- Fire extinguisher

- Tear gas

- Innahalation anaesthetic

- Dyes

Chemical properties

- oxidizing agent

- React with H2S

- React with H2O

- React with alkali

- React with non-metallic

- React with metal

Test to identify halide ions

- add conc. H2SO4 and heat

- Add AgNO3 followed by NH3

- Add Cl2 or acidic NaClO and then CCl4

Hydrogen halide (HX)

Preparation industrial:

HF - react CaF2 with H2SO4 at 200-350 °C

HCl, HBr, HI - react hydrogen and halogen

Uses HF

- manufacture AlF3, BF3, uranium tetrafluoride

- Manufacture fluorohalogen hydrocarbons

- Pickling stainless steel

- Glass etching and polishing

- Semiconductor manufacture

Uses HCl

- pickling metals

- Acid treatment of oil and gas wells

- Neutralization of protein and carbohydrates

- Regenation of ion-exchanger

- Manufacture of ClO2

Preparation laboratory:

HCl, HBr, HI

- react halide salt with conc. H2SO4

- React H3PO4 with halide salt in presence P2O5

Physical properties

- b.p decreases

- Thermal stability decreases

- Acid strength increases

Chemical properties

- React with metal above H in electrochemical series

- React with metal oxides, hydroxides, carbonates

- HF react with glass

- Reducing agent

Oxoacid

1. Hypohalous acid, HOX (+1)

2. Halous acid, HOXO (+3)

3. Halic acid, HOXO2 (+5)

4. Perhalic acid, HOXO3 (+7)

Lone oxygen increases, strength oxoacid increases

Oxyanion and salts of halogen

-ite (+1,+3)

-ate (+5,+7)

1. Hypochlorous acid, HClO(+1), hypochlorite ion , ClO-

2. Chlorous acid, HOClO(+3), chlorite ion, ClO2-

3. Chloric acid, HOClO2(+5), chlorate ion, ClO3-

4. Perchloric acid, HOClO3(+7), perchlorate ion, ClO4-

1. Hypochlorite ion

2. Halite ion

3. Halate ion

4. Perhalate ion

SITI KHADHIJAH BINTI NASIR

2021-01-14 14:48:30 UTC

Thank you Dr for today class. Here my summary for halogen group

Found as salts of halide ion because their high reactivity
Has 7 electrons valance
Down the group , increase in melting and boiling point, increase size of molecule and van der Waals forces

Fluorine

Has only 1 oxidation state because has the highest electronegativity. Thus it can easily remove an electron from nearby atom. Fluorine isoelectronic with noble gas
Can be obtained by electrolysis of HF dissolved in molten KF

Chlorine

Electrolysis of molten NaCl in Down cells
Electrolysis of brine in Kellner-Solvay method or using Chlor-alkali cell

Bromine

Extracted by passing Cl gas into concentrated sea water
Bromide ion is oxidized. Air passed through the seawater to vapourise bromine and transfer the gas into sulfite
Sulfite will reduce bromine to bromide ion
Chlorine gas is used to oxidize the bromide ion back to molecular bromine before distilling

Laboratory preparation

Reacting solution of halide ions with any substance that is stronger oxidizing agent
Reaction of metal halide with strong oxidizing agent
Chlorine can be made by oxidation of concentrated HCl with MnO2 of KMnO4
Solution of Cl2 in water is readily obtained by reacting bleaching powder or bleaching solution with HCl

Chemical properties

Displacement reaction (F₂ >Cl₂ >Br₂ >I₂ ) oxidizing power decrease
Reaction with H₂S
Reaction with water
Reaction with alkali solution ( general disproportionation reaction for X=Cl,Br, I)
Reaction with non metallic elements (halogens form covalent bond with non-metallic elements)
Reaction with metals

1.Halogen Halides

HF is manufactured industrially by reaction of fluorspar with sulfuric acid
HCl, HBr, HI are manufactured industrially by direct reaction of hydrogen and halogen . Laboratory preparation is the reaction of halide salts. But it not suitable for HBr and HI because some might be oxidized by the acid.
More suitable method is the reaction of phosphoric acid with halide salts in the presence of P₂O₅
Thermal stability HF>HCl>HBr>HI
Acid strength HF<

2. Oxoacid of Halogen

Cl, Br and I form 4 types of oxoacid
F only form 1
Preparation ,Hypohalous acid by hydrolysis of halogen. Halous acid by reaction of chlorine dioxide with hydrogen peroxide in the presence of barium. Halic acid prepared by reaction of iodine with nitric acid. Perhalic acid prepared from the catalytic oxidation of the corresponding halate followed by the addition of strong acid.
Acid strength (HOCl

3.Oxyanion and salts of halogen

Only hypochlorite ions and its salts are important
Sodium hypochlorite solution is called bleaching solution
Mixture of solid CaCl₂ and Ca(ClO)₂ is called bleaching powder.
Only sodium chlorite NaClO₂ is industrially important
Halate ion (+5) and its salts method of preparation is electrolysis of hot brine
NaClO₃ as defoliant and herbicide. KClO₃ as primary oxidant fireworks
Perhate ion and its salts . Sodium , potassium and ammonium perchlorate are particularly important industrially.
Perchlorate are mainly utilized fireworks.

TAN SIN JOE

2021-01-14 15:30:55 UTC

Summary:

Greek word: “hais (salt)” + “gennan (generate)” = Halogen
Increase m.p & b.p down group bc. Increase in van der waals forces (London dispersion force)

Lab preparation:

Soln (with halide ions) + stronger oxidizing agant -> dihalide gas
Metal halide + strong oxidizing agent(e.g. MnO4) –acid-> dihalide gas
Conc. HCl + MnO4/KMnO4 -> Cl gas
Bleaching powder/soln (CaCl2.Ca(ClO)2 / NaOCl) + HCl -> soln(Cl2 in water)

Chemical properties

1. Oxidizing agent (displacement rxn): high electronegativity – tend to gain e-s (decreases down group)

2. Disproportionation rxn: undergoes both oxidation & reduction (Cl -> Br)-> 2 different products ; halogen (oxidizing & reducing agents) + water (F2 & Cl2 can oxidized water based on Espr; 30% dissolved Cl -> HOCl)

Thermal stability: HF > HCl > HBr > HI
Acid strength HF << HCl < HBr < HI

*H-F bond very strong due to high -e- difference, F don’t let go H easily, bond needs more energy to break -> donating H+ low

Preparation: electrolyisis of HF (non-conducting) in molten KF (electrolyte)

Uses: fluorinated agentfor organic compound (refrigerator fluids, aerosol propellants, non-flammable anesthetic)

Preparation: electrolyisis of molten NaCl (/brine) in Down Cell (/using Kellner-Solvay method /Chlor-alkali cell)

*Down Cell- molten NaCl(l), produce Na metal at cathode, at high temp.

*Kellner-Solvay method- Brine (aq, conc., H2 gas + NaOH, at RT

Uses: bleach pigment(lignin) in paper in pulp/paper industry, water treatment, cleaning & sanitation

Test: Cl-

+ conc. H2SO4 -heat> HCl gas released

+ AgNO2 (aq) -> white precipitation dissolved in NH3

+ Cl2(aq) / NaClO(aq) - + CCl4(l)-> no rxn

Preparation:

1. pass Cl gas -> conc. sea water (Br- -> Br),

2. air -> seawater (vaporise Br transferred into sulfite, SO32- reduce Br -> Br-)

3. Cl gas -oxidise Br- -> Br

4. Distill pure Br out

Test: Br-

+ conc. H2SO4 -heat> HBr, SO2, Br2

+ AgNO2 (aq) -> yellowis =h precipitate dissolved in conc. NH3

+ Cl2(aq) / NaClO(aq) - + CCl4(l)-> Br2 + brown CCl4 layer

Test: I-

+ conc. H2SO4 -heat> SO2, H2S, I2

+ AgNO2 (aq) -> yellow precipitation sparingly dissolved in conc. NH3

+ Cl2(aq) / NaClO(aq) - + CCl4(l)-> no rxn

HYDROGEN HALIDE, HX: reducing agent (strength: HCl < HBr < HI); 6HF + glass, SiO2 -> H2SiF6 + 2H2O

Preparation:

Indstrial:
fluorspar, CaF2(s) + H2SO4(aq, conc.) -200-350C-> HF(g) + Ca(HSO4)2 (aq)

Lab:

Halide salts (e/g/ NaCl(s)) + conc. H2SO4(l) -> HX(g) + Na2SO4(aq)
Phosphoric acid, H3PO4 (poor oxidizing agent) + halide salts, MX -P2O5-> M3PO4 + HX

HCl, HBr, HI

Preparation: direct rxn of H and halogen

OXOACID

Types: 4 for Cl, Br, I ; 1 for F (HOF, extremely difficult to oxidized)
Acidity increases as # O, o.s increases

Hypohalous acid, HOX (o.s:+1): weak acid, oxidizing agent

Preparation: hydrolysis of halogen: disproportionation rxn (Cl, Br, I are slightly soluble in water)

*Hydrolysis of dichlorine oxide, Cl20 -> HOCl

Halous acid, HOXO (o.s: +3):

Preparation: chloring dioxide + hydrogen peroxide -Ba(OH)2-> chlorous acid; Barium chlorite precipitated + H2SO4 -> chlorous acid

only HOClO is important -more stable than HOBrO and HOIO

Halic acid, HOXO2 (o.s:+5):

I + HNO3 -> 2HOIO2 + 10NO2 + H2O

*can be easily prepared & isolate fr its aq soln

Perhalic acid, HOXO3 (o.s: +7): strong & powerful oxidizing agent, oxidizes organic materials explosively when heated

Perchloric acid, HOClO3, periodic acid, HOIO3

Preparation: Catalytic oxidation of the corresponding halite, XO3 + strong acid

Evaporation of HOIO3(aq) -> orthoperiodic acid, H5IO6

#Lone O attached to central atom affects acidity of oxoacids: #lone O increases, oxoacid-> better p+ donor
Strength of oxoacid of Cl: HOCO < HOClO < HOClO2 < HOClO3
O: Very electronegative, has strong tendency to pull e- density away -> increases central atom’s ability to draw e- density away fr H-O bond, easier H+ be released

Names of oxyanions of halogens:

Ending: low o.s -ite(+1,+3), high o.s -ate(+5, +7)
Prefixes: lowest o.s hypo-, highest o.s per-

Hypochlorite ion(+1) and its salt

Only hypochlorite ions, ClO- and its salt are important

Preparation:

1. Chlor-alkali industry- Electrolysisof colf brine (15C)

Cl gas (anode) + OH- ion(cathode)/ NaOH -> Cl- + H2O / cold: NaOCl(bleching soln) + H2O; hot: NaCl + NaClO3 + H2O

2. CaO/ Ca(OH)2 + Cl -> CaCl2 + Ca(OCl)2 (bleaching powder)/ CaCl2 + Ca(OCl)2 + H2O

Hypochlorate ion in soln (aq) undergo disproportionate rxn -> X- + XO3-
Rate of rxns: ClO- (bleaching/oxidizing agent, disinfectants) < BrO-(unstable) << IO- (not exist in soln)

Halite ion(+3) and its salt:

Preparation: ClO2 + NaOH + H2O2 -> NaClO2 + H2O + O2

Sodium chlorite, NaClO2 is industrially important: bleaching, oxidizing, deodorizing agent of odorous industrial emission, bleaching agent for paper pulp, defoliant, herbicide

Possible to convert mixture(chlorate +5 and hypochlorite +1 ions) into soln(chlorite +3)

ClO3- + ClO- -> ClO2

*KClO3: primary oxidation in fireworks and matches, source of obtaining O gas in lab

Halate ion(+5) and its salt:

Preparation:

electrolysis of hot brine(70C): X2 + OH- -> X + H2O
Bromate & iodate salt - Oxidation of halide ion(+3) by hypochlorite ion: X + ClO- -> XO3- + Cl-

Uses:

iodates – source for production of sulphate ion
IO3- primary std soln for determination of iodide
iodate ion reacts quantitatively with iodide -> iodine + thiosulphate ion, S4O6-2
Na perchlorates: electrochemical synthesis NaClO3 + H2O -> NaClO4 + H2
MCl + NaClO4 -metathesis-> K & NH3 salts
*NH3 perchlorate exclusively used as oxidation agent in rocket

NURUL NASYRAH BT SAHAR

2021-01-15 02:18:50 UTC

Thank you Dr for the explanation about this topic
here are my summary about group VIIA (HALOGEN)
-found as the salts of halide ion because of the reactivity
-melting point, boiling point ,size of molecules increases down the group
-van der Waals forces also increase down the group

FLOURINE
-has 1 oxidation state
-due to the high electronegativity, its can easily remove an electron from nearby atom
-isoelectronic with a noble gas
-industrial preparation (electrolysis of HF dissolved in molten KF)

CHLORINE
-industrial preparation (i)electrolysis of molten NaCl in Downs Cell
(ii)electrolysis of brine in Kellner- Solvay method or Chlor-alkali cell

BROMINE
-extracted by passing chlorine gas into concentrated sea water,bromide ion oxidized to molecule bromine,air passed trough sweater to vapourise bromine,transfer gas into sulfite,sulfite reduce bromine to bromide ion ,Cl2 used to oxidized bromide ion to bromine before distill pure brmine out.
-lab preparation (reacting bromide ion with chlorine)

HYDROGEN HALIDE
-industrial preparation (HF) manufactured by the reaction of fluorspar with H2SO4
-HCl,HBr,HI are manufactured by direct reaction of hydrogen and halogen
-uses of HCl (picking f metals,acid treatment of oil and gas,manufactured of ClO2
-lab preparation(reaction halides salts with conc.H2SO4
-HCl,HBr,HI preapared by reaction of phosphoric acid with halides salts in presence P2O5
-thermal stability decrease and acid strength increase down the group

OXOACID OF HALOGEN
-Cl,Br,I form 4 types oxoacid and F form 1 cause difficult to oxidize it
i)hypohalous acid(+1)-hydrolysis of halogen(disproportionation reaction
ii)halous acid(+3)-chlorous acid prepared by reaction of chlorine dioxide with H2O2 inpresence of barium.
iii)halic acid (+5) -only iodic acid can easily prepared and isolated its aqueous solution with HNO3
iv)perhalic acid (+7)-prepared from catalytic oxidation followed by addition strong acid.
-more number of lone oxygen,more acid

OXYANION & SALTS OF HALOGEN
-ending *ite(+3,+1),*ate(+5,+7)
-hypochlorite ions(+1)- prepared by electrolysis of cold brine ,reaction CaO or Ca(OH)2 with chlorine
-halite ion (+3) -salts produced by reaction ClO2 with NaOH and H2O2 (method preparation by electrolysis of hot *70 degree celcius* ,oxidation of halide ion by hypochlorite ion)
-uses KClO3 as source of obtaining oxygen gas in lab experiment ,as primary oxidant in fireworks and matches)

TAN JING XUAN

2021-01-15 14:35:40 UTC

Thank you dr for the lesson. Here is my summary about this topic:
HALOGEN
-"Hals" means salt and "gennan" means generate
-combined with metals and form salts.
-found as salts of the halide ion due to high reacitivity.
-Fluorine has the highest electronegativity among all the elements
-Chemical properties: as an oxidizing agent(high electronegativity), Displacement reaction (oxidizing power decrease down the group), Reaction with H2S, reacts with water in a disproportionation reaction (except F), form covalent bonds in compounds with non-metallic elements.

Fluorine
-only has 1 oxidation state which is -1 because when one electron is added, the outermost p orbitals will be completely filled and fluorine is then isoelectronic with a noble gas.
-In industrial preparation, F is obtained by an electrolysis of HF dissolved in molten KF
-mainly used as fluorinating agent for organic compounds.
Chlorine
-In industrial preparation, chlorine is obtained by

electrolysis of molten NaCl in Downs Cell
electrolysis of brine in Kellner-Solvay method or using Chlor-alkali cell

-Uses: in manufacture of organic and inorganic chemicals, as bleaching agent, in water treatment, in cleaning and sanitaiton.

Bromine
-In industrial preparation, Br extracted by passing chlorine gas into concentrated sea water.
-mainly utilized in the manufacture of organic chemicals.

Hydrogen Halides (HX)
Industrial preparation

HF - reaction of CaF2 with sulphuric acid
HCl, HBr, HI - direct reaction of hydrogen and halogen.

Laboratory preparation

reaction of halide salts with concentrated sulfuric acid (not suitable for HBr and HI)
reaction of phosphoric acid with halide salts in the presence of P2O5.

-Thermal stability of HX decreases down the group.
-Acid strength of HX increases down the group.

Oxoacid of Halogen
-Cl,Br and I form 4 types of oxoacid while F only form one due to difficulty to oxidize it.
(a) Hypohalous acid (+1)
-obtained by hydrolysis of halogen (disproportionation reaction)
-weak acid
-oxidizing agents
(b) Halous acid (+3)
-HOClO is more stable than HOBrO and HOIO
(c) Halic acid (+5)
-HOIO2 can be easily prepared by reaction of iodine with nitric acid.
(d) Perhalic acid (+7)
-strong acids and powerful oxidizing agent.
** the number of lone oxygens attached to the same central atom affects the acidity of the oxoacids. (acid strength of oxoacid of chlorine: HOCl
Oxyanion and salts of halogen
hypo- lowest oxidation no.
per- highest oxidation no.

Hypochlorite ions(+1) and its salts are important
Halite ion (+3) - NaClO2 is industrially important.
Halite ion (+5)

NUR QISTINA IZZATI BT MOHD FITRINAZRIN POON

2021-01-16 09:25:46 UTC

Thank you dr sheela for the lessons.
GROUP VIIA HALOGEN

have 7 valence electrons
found as salts of the halide ion because of their high reactivity
melting and boiling point increases , increase size of molecules and van der Waals forces down the group
Fluorine only has 1 oxidation state because its has high electronegativity and can easily remove an electron
Fluorine can be obtained by electrolysis of HF dissolved in molten KF
Fluorine has the highest electronegtivity
Chlorine can be obtained by electrolysis of molten NaCl in Downs Cell' and electrolysis of brine in Kellner-Solvay method using Chlorine alkali cell
Bromine is extracted by passing chlorine gas into concentrated sea water where the bromine ion is oxidized to molecular bromine.
Lab preparation : reacting a solution of the halide ions with any substance that is a stronger oxidizing agent. / Reaction of metal halide,MX with strong oxidizing agent / Cl can be made by oxidation of concentrated HCl with MnO2 or KMnO4 / Solution of Cl2 in water is readily obtained by reacting bleaching powder , CaCl2.Ca ( Cl0)2 or bleaching solution ,NaOCl with HCl
Application of elemental halogen
Chemical properties : F2>Cl2>Br2>I2
Tests to identify halide ions
Compound of halogen : Hydrogen Halides : HF,HCl, HBr,HI
Stability of HX : HF>HCl>HBr>hi
Strength of HX :HF
Acid strength of HX : HF
Acid HF is a weak acid because bond between fluorine and hydrogen is very strong due of very high electronegativity difference.
Oxacid of Halogen : HOXO3, HOXO2, HOXO, HXO
Hypo : lowest oxidation number
Per- highest oxidation number
Hypohalous acid , Halous acid , Halic acid , Perhalic acid
Acid strength of oxacid of chlorine : HOCl , HOClO , HOClO2 , HOClO3

- So far i have no additional question for this topic..Thank you dr.

AHMAD IMRAN BIN AHMAD BASRI

ahmadimran — 2021-01-20 09:09:13 UTC

Thank you for the lecture. This will be my summary for the topic
Halogen
- Hals:salt and gennan:generate
- Flourine has the highest electronegativity
- Can easily remove an electron from nearby atom
Physicochemical properties
- Has 7e valence electron and need 1 electron to achieve octet configuration
- Melting and boiling point increase down the group
- Increading Van der Waals force down the group
- Size of molecule increase down the group
Fluorine
Industrial preparation
- Obtained by electrolysis of HF dissolved in molten KF
Chlorine
Industrial preparation
- Electrolysis of molten NaCl in Downs cell
- Electrolysis of brine Kellner-Solvay method or using Chlor-alkali cell
Bromine
- Extracted by passing chlorine gas into concentrated sea water.
- Then, air is passed through seawater to vapourise bromine
- Then, transfer into sulfite solution
- Reduce bromine to bromide ion
- Last, chlorine gas will oxidize bromide ion into bromine
Laboratory preparation
- React bromide ion with chlorine
1. Hydrogen Halides
HF
- Manufactured industrially by reaction of fluorspar
HCl, HBr, HI
- Manufactured industrially by direct reaction of hydrogen and halogen
- Manufactured laboratorily by reaction of halide salt but not suitable for HBr and HI
- More suitable method of preparation of HX is the reaction of phosporic acid with halide salts in presence of P2O5
2. Oxoacid of Halogen
- Hypohalous acid
- Halous acid
- Halic acid
- Perhalic acid
3. Oxyanion and salts of halogen
Hypo - lowest oxidation number
Per - highest oxidation number

MUHAMMAD AKMAL AQIL BIN ROZIMAN

2021-01-20 13:01:43 UTC

Thank you dr for the explanations in the lecture. Here is my summary:
Group VIIA
-Also known as halogens
-Halogens : Derives from the Greek words hals(salt) & gennan(generate)
- Has 7 valence electrons & achieve a octet configuration by covalent bonding or accepting an electron
- Going down the group, the boiling & melting point increases due to the increase of van der Waals forces.
- Size of molecule increases while ionization energy decrease as going down the group
- Due to high electronegativity, halogens are used as oxidizing agents
- Forms covalent bond with non-metals & ionic bonds with metallic elements
- Fluorine has the highest electronegativity of all elements therefore it can easily remove an electron from a nearby atom
- Fluorine is mainly used as a fluorinating agent for organic compounds while chlorine is used in manufacturing of organic & inorganic chemicals
Hydrogen Halides
- Examples of hydrogen halides : HF, HCl, HBr & HI
- HF is industrially prepared by reacting fluorspar, CaF2 with H2SO4 at a certain temperature
-HF is used in the manufacturing of fluorohalogen hydrocarbons
-HCl is prepared by direct reaction of hydrogen gas with chorine gas
Thermal stability for hydrogen halides decreases while acid strength increases when going down the group
Oxoacid of halogens
- Cl, I& Br can form 4 types of oxoacid while F can only form 1
- Oxoacid of halogens can be differ by the its oxidation number
- Highest oxidation number is +7 while lowest oxidation number is +1
-Depending on the number of oxygens bonded with the central atom, the acidity of the oxoacids can be determined & differentiate.
- the prefix hypo- & per- are used to indicate the highest & lowest oxidation number of the oxoacid
-Examples of oxoacid of halogens are NaClO3 & KClO3
- KClO3 is a primary oxidant in fireworks and matches And used as an oxygen source in laboratory experiments.