# data[].attributes.body
First of all, im sorry dr. I did the whole summary for group IIIA but then deleted that one thinking that another one is my summary 😭🙏🏻 Here is my summary:

Trends - exhibit +3 oxidation state, changes to +1 down the group (inert pair effect), size increases, electronegativity Ga>Al

Properties - B cannot expand valence shell, IE very high, High hydration energy(except B), B never exist as B3+(high charge density), metallic character increases, B&Al not reactive(icosahedral, stable oxide layer), acidity strength decreases down the group

Compounds of group IIIA

1. Oxides (normal oxide)

-preparation—heat in O2, thermal decomposition of nitrate, hydroxide

2. Halides

- B(monomer), others(dimer)

- Preparation—heating, halogenation, dissolve oxide/hydroxide/ carbonate in HX

Anomaly of Boron - non metal, acidic, BCl3&BX3(monomer, covalent), does not replaced H from HCl & H2SO4

Diagonal Relationship (B&Si)

1. Hydrides easily vapourized, covalent, reactive, easily hydrolysed by H2O or acid

2. Halides easily hydrolysed by H2O, covalent

3. Boric/silici acids—weak acid

4. Non-metal elements

5. Similar properties of oxides

BORON

- existence—kernite, borax, colmanite, 10B, 11B

- Preparation—react borax in HCl, electrolysis KBF4

- Properties—shining black nonmetal,semiconductor, high melting point, icosahedral, extremely reactive(powder), reduces H2O vapour to H2(red-hot)

- Application—neutron absorber, cancer treatment, high bombardment steel, high temperature semiconductor

Compounds of Boron

1. Hydride(borane)

- preparation—reduction of BCl3, hydrogenation of BCl3

- Properties(diborane)—gas,toxic,green flame, fast hydrolysis in water/alcohol, react vigorously in acid/Cl2

- Structure — has bridging-H (electron deficient structure)

- Application—reducing agent, supply of H2

2. Oxides

- Preparation—burn B in O2, fuse solid boric acid

- Properties—acidic,react slowly in water,form coloured borate glass (when fused with other metal)

- Application—Pyrex

3. Hydroxide (boric acid)

- preparation—hydrolysis BCl3, react dilute HCl with borax

- Properties—white needle crystal, soluble in hot water, easily vapourized, weak monobasic acid, Lewis acid, react with alcohol form borate ester, weak acid in aqueous but strong in diol, decomposed to metaboric acid, complete fusion gives glass form, as antibacterial additive

- Borate- fusing boric acid with metal oxide

- Borax-fusing transition metal->coloured glass

- Uses—coloured glass, Pyrex glass

4. Halide(BX3)

- preparation—direct halogenation of B with halogen, (BF3–heat B2O3+CaF2 or NH4BF+H2SO4

- Structure—trigonal planar

- Properties—covalent, easily vapourized, strong Lewis acid(BF3<BCl3<BBr3>BI3)->BF3 weak cause electronegativity F very high, BI3<BBr3 cause steric effect), vigorous reaction with H2O, complete hydrolysis of BCl3&BBr3

- Application—Friedes Craft catalyst

5. Nitride(BN)

- preparation— heat B2O3 in NH3 (1200°C)

- Properties— graphite type, slippery, electric insulator, white refractory solid, BN layer changes to sphalerite cube

*BORAZINE

- preparation—react diborane+ammonia

- Properties—liquid at RT, structure similar to benzene, react with HCl, react as reducing agent, sensitive towards moisture

ALUMINIUM

-occurrence—8.8% in earth crust, as aluminusilicates, as bauxite ores, as cryolite

Preparation—Bayer process,Hall-Heroult process

Properties—react directly with O2,N2,S and halogen, react with HCl, react with H2SO4, does not react with HNO3, react with base

Uses—catalyst for dehydration of alcohol to olefin, prepare alloy, wrapper/food containers, transport engine, welding alloy, window frames, cable electric

Compounds of Aluminium

1. Oxide(alpha, gama)

- preparation—Bayer process, heat aluminium hydroxide

- Application—refractory, catalyst in dehydration of alcohol to alkene, as stationary phase in column chromatography, used as support for transition metal, gemstones

2. Hydrate

- exist—diaspore(alpha), boehmite(gama)

- Preparation— boil Al+NH3

3. Hydroxide (AlOH3)->Gibbsite

- Preparation—addition NH4OH into Al3+ solution, acidification of aluminate with CO2

- Properties— white solid, amphoteric

- Uses— mordant, coagulating agent

4. Halide(AlX3)

*AlF3(monomeric)

- Properties— ionic solid, soluble in water, form salt with alkali metal, does not behave as Lewis acid

*AlCl3(dimeric-Al2Cl6)

- Industrial Preparation — passing dry Cl2/HCl over hot Al metal, react Al with HCl, Heat Al2O3 with C or Cl2

- Laboratory Preparation— use hot column reactor

- Properties— white solid, covalent, sublimes at 180°C, dimer up to 400°C, monomer above 400°C, complete at 800°C

5. Sulphate(Alum)

- monovalent & trivalent metal ions

- Common alum : potash alum

- Properties— colourless hexagonal crystal, soluble in water, alum hydrolysed in water to acidic solution

- Uses—purification of water, mordant in dyeing, tanning leather & sizing paper, styptic

# data[].attributes.body
Thank you Dr for the lecture on group 3. Here is what i can summarised:

- Boron form acidic oxide and aluminium form amphoteric oxide.

General properties:
-  metallic character increases down the group
-  All elements show the stable valency of +3
- Boron never exist as discrete or hydrated
- Boron and Aluminum is not reactive
- Boron has diagonal relationship with Silicon
- Boron can be formed with the reaction of borax and electrolysis of Potassium Fluoroborate in a mixture of Potassium Chloride and Potassium Fluoride.
- Aluminum can be prepared with Bayer process and and Hall-Heroult process.

# data[].attributes.body
Thank you Dr for the explanation in the video.

Summary
1) The trend for ionic, covalent & metallic increases as going down the group.
2) Boron forms acidic oxides while aluminum forms amphoteric oxides
3) All elements in Group IIIA have 3 valence electron therefore have high ionization energy
4) Boron is used in cancer treatment therapy while aluminum is used as alloys in vehicles components.
5) Boron shows non metallic characteristics while most Group IIIA shows metallic characteristics.

# data[].attributes.body
Thank you Dr Sheela for the lecturer.
Summary :
1.  The trend  covalent,metallic and ionic radii of the down the group is increases
2. Their electronegativity from Ga to Al is increase due to the nuclear charge
General Properties:
1. Boron cannot expand the valence electron
2. ionization energy is high
3.  aluminium oxide prepared by bayers process
4.Alum is double sulphate of monovalent and trivalent

# data[].attributes.body
Tq dr for the explanation during the classes.
Here are the summary for group IIIA:
-covalent,metallic and ionic radii increases
-electronegativity increase but Al is more electronegative than Ga due to increase nuclear charge in Ga.
-Boron form acidic oxides,form flammable,gaseous hydrides
-Boron is electron deficient ,making all neutral compounds to Lewis acids.
GENERAL PROPERTIES
- Boron cannot expand valance shell
- all element show stable valency of +3,never exist as discrete or hydrated.
-acidity decrease down the group due to decrease in electronegativity and covalent bond character.
OXIDES
-all elements form normal oxide.
-preparation by heating in oxygen and thermal decomposition of nitrates or hydroxide
-thermal stability decreases down the group
HALIDES
-preparation by heating the element,halogenation
of mixture oxide and coal,dissolving an oxide,hydroxide,carbnate.
DIAGONAL RELATIONSHIP(B & Si)
-Hydrides easily vapourized,halides(covalent)-easy hydrolysed by water,non metal elements,oxides(covalent acid,plymeric macromolecules)

1)BORON
-preparation(reaction of borax in HCl),(electrolysis of KBF4)
-Boron Hydrides known as borane,preparation  by reduction of boron trichloride and hydrogenation of BCl3)
-special structure of diborane,both B are connected by bridging hydrogen
-Boron hydroxide known as boric acid,preparation by hydrolysis of boron trihalide and reaction between dilute HCl
-acting as lewis acid
-Boron oxides ,preparation by burning B in oxygen and fusing solid boric acid.
-Boron halides ,preparation  by direct halogenation of boron with halogen, have tigonal planar with B sp2 hybridization.
-Boron nitride, preparation by heating B2O2 in ammonia at 1200 degree celcius.
-have similiar structure with benzene but different properties.

2)ALUMINIUM
-preparation using 2 process by Bayer process and Hall- Heroult process (electrolysis of Al2O3)
-Aluminium oxides, preparation by Bayer process and heating Al(OH)3  to beta alumina ---->alpha alumina
-Aluminium hydrate , known as aluminium hydroxide oxide ,exist in 2 form (alpha-AlO.OH & beta- AlO.OH)
-preparation by ammonium
-Aluminium hydroxide ,preparation by additin of ammonium hydoxide into Al3+ sloution and acidification of aluminate solution with CO2.
-Aluminium halides, ionic solid,soluble in water des not behave as lewis acid because X rich of electron
-preparation by passing dry Cl2/HCl over hot metal,reaction between Al and HCl/HBr, heating aluminium oxide with carbon and chlorine.(industrial).
-preparation by using hot column reactor for preparation anhydrous.(lab)
-structure as dimer
-ALUM (SULPHATE)
-name given to double sulphate of monovalent and a trivalent metals ion
-POTASH ALUM (colourless hexagonal crystal,soluble in water and hydrolyze in water to acidic solution).

# data[].attributes.body
Thank you Dr for you detailed and well explainations. Summary for group IIIA :

1) For Boron :
#The trends by going down the group.
- electronegativity for Ga is more than Al due to inreased nuclear charged.
- the size will be increased.
# The chemical properties.
- boron forms acidic oxide ,B2O3
- boron from flammable, gaseous hrdrides.
#General properties.
-non metal
-formed as an icosahedral unit of crystal
-cannot expand valence shell
- never exist as discrete B3+ or hydrated B(H2O)4
#Diagonal relationship (B &Si)
- hydrides are easily vapourised , covalent, reactive
- Boric/silicic acids : weak acid
- non metal elements
- covalent acid and polymeric macromollecules
#Boron exist as kernite, borax, colmanite
# Preparation
- reaction of borax in HCl
-electrolysis KBF4 in a mixture of fused KCl and KF at 800 C
#Properties
-black non metal
- semiconductor
- high melting point
#Applications
- high bombardment
- high purity boron
#Boron hydrides
- reduction of boron trichloride
- hydrogenation of BCl3
- exist as gas
- extremely reactive , flmmable in air ( green flame)
- electron dificient structure
#Boron oxide
- burning B in O2
-acidic oxide
-produced borosilicate glass
#Boron hydroxide
- known as boric acid
-hydrolysis of boron trihalide
- white needle cyrstal
- easily vapourised
-react with alcohol
# Boron halide
- direct halogenation of boron
tigonal planar / sp2
-covalent , easily vapourised
-complete hydrolysis of BCl3 and BBr3
# Boron nitride
-heatinng B2O3 in ammmonia
-graphite type
- electric insulator
-liquid at room temp
similar structure like benzene but different properties

# data[].attributes.body
GROUP IIIA:
-covalent, metallic and ionic radii increase down the group
-electronegativity Ga>Al due to increases of nuclear charge in 4p subshell

Chemical properties:
-B form acidic oxides while Al form amphoteric oxides
-B is flammable, gaseous hydrides
-Aluminium hydride: solid
-B is electron deficient and making compounds Lewis acid

General properties:
-cannot expand valence electron because of incomplete shielding in s shell
-all elements are +3 valence except Tl +1 due to inert pair electron effect
-ionization energy high
-form hydrated M(H2O)6^3+ except B
-metallic character increases
-B and Al does not reactive

Boron:
• Oxides
-burning oxygen
-fusing solid boric acid
-produced borosilicate glass (Pyrex)

• Hydrides (Borane)
-reduction of boron trichloride
-hydrogenation of BCl3
-diborane (B connected bridging with H2)

• Hydroxides
□ boric acid
-hydrolysis boron trihalide
-reaction between dilute HCl and borax
□ borate
-fusing boric acid and metal oxide
-polyoxyborate anion, sharing oxygen
-borax fusing with transition metal

• Halides
-direct halogenation with halogen (high temperature)

• Nitrides
-heating B2O3 in ammonia (1200°C)
-graphite type, slippery, electric insulator, white refractory solid

• Borazine B3N3H6
-reaction between diborane and ammonia
-reactive towards HCl
-reducing agent, sensitive towards moisture, e- is localized

Anomaly Boron:
-nonmetal, formed icosahedron
-boron chloride: monomer
-does not replacing H in oxidizing acid

Diagonal relationship B & Si:
-nonmetal
-hydrides easily vapourized
-halides, covalent
-borix/sillic acid - weak acid
-oxides - covalent acid and polymeric macromolecules

Aluminium:
-Baeyer process and Hall Heroult process (electrolysis Al2O3)

• Oxides
-bayer process
-heating aluminium oxide

• Hydroxides
-addition ammonium hydroxide into Al3+ solution
-acidification aluminate solution with CO2

• Halides
□ industrial
-dry Cl2 or HCl over hot metal/molten Al
-reaction between Al and HCl/HBr
-heating aluminium oxide with carbon chlorine
□ laboratory
-hot column reactor of anhydrous

• Alum
-double sulphate of monovalent and trivalent metal ions

Thank you dr for the explanation of this topic :)

# data[].attributes.headline
Nur Qistina izzati Binti Mohd Fitrinazrin Poon 

# data[].attributes.subject
Nur Qistina izzati Binti Mohd Fitrinazrin Poon 

# data[].attributes.body
Group IIIA
BORON
1 .Non-metal.
2. Boron forms acidic oxides,B2O3
3. Boron is electron deficient and making all its neutral compounds Lewis structure.
4. Boron never exist as discrete B3+ or hydrated B(H2O)4 3+ due to very high charge density.
5. Icosahedral,B12 : 12 vertices,20 faces and 30 sides.
6.Anomaly : non-metal,B2O3 is an acidic, Boron chloride ,BX3 is monomer covalent, others dimer,M2X6 and Boron does not replaced H from non oxidizing acid (HCl / H2S04)
7. Diagonal relationship B and Si
8. Prepared by reaction of Borax in HCl and electrolysis KBF4 compound in a mixture of fused KCl and KF at 800 deg celc.
9. Black non-metal element but shining likes metal, semiconductor properties and high melting point.
10. Uses : Neutron absorber ( boron alloy ) , cancer treatment.
General properties
1. Covalent ,metallic and ionic radii increases from B to Ti .
2. B : non-metal
Al : weak metal
Ga : metalloid
In & TI : metal
3. B and Al seems not reactive due to B formed as an icosahedral unit of crystal,B12 whereas Al form stable oxide layer on its surface.
4. All elements form normal oxide only , M2O3. Thermal stability of oxides decreases down the group.

ALUMINIUM
1.most abundant element in earth crust (8.8%).
2. As bauxite and cryolite.
3. Prepared by BAYER PROCESS & HALL-HEROULT PROCESSA.
4. Do not react with HNO3 due to the formation of an oxide layer on the surface.
5. Uses : Aluminum powder (catalyst) , wrappers, food container , transport(airplanes) , electrical(cable)
6. Al203,AlO.oH , Al(OH)3 , AlX3 , Alum ( properties , structures and uses)

# data[].attributes.body
Thank u Dr for the class :3

Group IIIA which called the boron family

·         General properties

o   All element show stable valency of 3+

o   Boron never exist as discrete B3+

o   Metallic character increase down the group

o   B and Al seems not reactive

·         Strength of acidity decrease down the group because

o   Decrease in electronegativity

o   Decrease in covalent bond character

·         Preparation (oxides)

o   Heating in oxygen

o   Thermal decomposition of nitrate or hydroxide

·         Preparation (halides)

o   Direct combination of elements

o   Halogenation of a mixture of oxide and coal (as reducing agent)

o   Dissolving an oxide or hydroxide or carbonate in HX

·         Diagonal relationship (B and Si)

o   The hydrides are easily to vaporized,  covalent, and reactive. Easily hydrolyzed by water

o   Halides is covalent

o   Boric/silicic acids are weak acid

o   Non-metal element

o   B2O3/SiO2 are covalent acid, polymeric

·         Preparation of boron

o   Reaction with borax in HCL

o   Electrolysis KBF4 compound in a mixture of fused KCL and KF at 800 degree celcius

·         Application

o   Neutron absorber

o   Cancer treatment

o   High temperature semiconductor

·         Compound of boron

o   Oxides

o   Hydroxides

o   Halides

o   Nitride

·         Preparation of aluminium

o   BAYER PROCESS

o   HALL-HEROULT PROCESS

·         Chemical properties

o   React with HCL to give H2 gas

o   React with H2SO4 to give sulphate and SO2

o   Do not react with HNO3 due to the formation of an oxide layer on the surface react with base to give aluminate ion and H2

·         Uses

o   In transport

o   Molding alloy

o   In constructions

o   Electrical which is cable

·         Aluminium compound

o   Oxide

o   Hydrate

o   Hydroxide

o   halides

question :
For the preparation of Boron Hydroxide, can we use kernite or colmanite instead of borax ?

# data[].attributes.body
Thank you Dr. for the classes.
This is my summary for Group IIIA:

1) Trends down the group
-The size increases.
- Electronegative for Ga> Al because Ga has increased nuclear charges of 4p elements due to poorly  shielding 3d electrons.
-Boron form acidic oxide while aluminium forms amphoteric oxide.
-Boron form gaseous hydride, aluminium hydride is solid.
Boron is electron deficient and make compound to lewis acids.

2)  Diagonal Relationship Of B&SI
-The hydride produced is easily vapourized, covalent and very reactive.
-Its halides is covalent so it is easily hydrolyzed by water.
-Its acid formed is a weak acid
-It is non metal element
-Its oxides is a covalent acid.

3)Boron (Kernite,Borax,Colmanite)
-Prepare Boron
-Reaction of Borax in HCL
-Electrolysis KBF4
-Properties
-Black non-metal but shine          like metal
-Semiconductor properties
- High melting point
-Boron powder is extremely
reactive.
-Compounds of Boron
i)Boron Hydrides (Borane)
-Prepare by
-reduction of boron trichloride and hydrogenation of BCL3
-Properties
-Toxic, very reactive, quickly hydrolysis in water.
ii)Boron Oxide
-Prepare by
-Burn Boron in oxygen and   Fusing Solid
- Is an acidic oxide
iii) Boron Hydroxide (Boric Acid)
-Prepare:
- Hydrolysis Boron trihalide
-reaction between dilute HCL
Properties:
-Soluble in hot water, white needle crytal
iv) Boron Halide

Preparation:
Direct halogenation of boron with halogen at high temperature
Properties:
-covalent and easily vapourize,strong lewis acid.
v)Boron Nitride
Prepare by heating B2)3 in ammonia at 1200 celcius
Properies: slippery and used as lubricant, electric insulator.

Aluminium
-Prepared by Bayer Process and Halt-Heroult Process
-Compounds Of Aluminium
i) Aluminium Oxides.
-form alpha alumina and gamma alumina
-Prepare by Bayer Process and by heating aluminium hydroxide
ii)Aluminium Hydroxide
-Prepare by adding ammonium hydroxide into al3+ solution
and acidification of aluminate solution with CO2
iii) Aluminium Halide
-Prepare by reaction between Al and HCL/HBr
-White solid, covalent.
iv) Alum
-double sulphates of monovalent and trivolent metal ions.

# data[].attributes.body
Thank you Dr. for the classes.

Summary:
- the lewis acidity of the boron halide is based on the size of the halides.
- The trend of the lewis acidity of the boron halide is increasing down the group of halides. However there is a different when reach to to boron iodide as its lewis acidity is lower than the boron bromide which is because the steric effect.

-Boron hydroxide or we called it boric acid is acidic because it is a non metal.

-the borazine did not conduct electric due to its lewis structure as there is no any delocalized electron around the compound because of the arrangement of the atoms in the structure(N-B-N). Plus, nitrogen and boron have a different of electronegativity so the bonding between two atoms are very strong and hard to be separate Therefore, borazine cant conduct electricity.

-alumina can be produced by bayer process while aluminium can be produced by the bayer process and hall-heroult process.

-the color on the different gem is because the impurities of alumina in the gem.

-aluminium halide also have a dimeric struture which form by a the halides bridge

-potash alum can purify the water when dissolve it into water and then the ions that separated from the potash alum will reacted with the dirt or anything in the water to become a larger compound, Therefore, the worker can easily filtered it out can get the clean water. Plus, the larger compound with higher density will sink under the water so the user will not get the dirt when filling or consuming the water.

-alum is form by monovalent and trivalent metal ions and having the hydrated water formulae in their chemical formula.

# data[].attributes.body
Thank you Dr for today’s lesson.
GROUP IIIA

Trends

1)covalent,metallic and ionic radii increases

2)electronegativity decrease.

But electronegativity Ga>Al , because Ga increased nuclear charge of 4p elements,presence of poorly shielding electron 3d electron(also f)

3)boron oxide acidic,polymeric structure -aluminium oxide amphoteric

4)Boron gaseous hydride,Al hydride solid

5)Boron different (cannot expand valence shell ,incomplete shielding)

6)All stable valence +3,Ti not due inert pair effect

7)Boron not exist B3+/hydrated bcs high charge density ,polarizes water

8)metallic character increases

9)B & Al seem not reactive (B an icosahedral unit,Al stable oxide layer on its surface)

10)act as electron acceptor –Lewis acid,

strength acidity decreases down group(IE decrease,covalent bond character decrease)

Complexation of ion

1)Al3+-Ti3+ Coordination number from 4sp3-6sp3d2 because can expand d orbital

2)B only 4 coordinated because 2s and 2p m form sp3 hybridize

Anomaly boron : non metal,formed isocahedron,acidic oxide,weak acid hydroxide,covalent and dimer for boron chloride,not replaced H from HCl/H2SO4

Diagonal B&Si :

1)hydrides(vapourized,covalent,reactive,easily hydrolyzed w water n acid),

2)halide(covalent)

3)boric acid(weak acid ,polyanionic acid form)

4)non metal

5)B2O3/SiO3-covalent acid

(A)BORON
(KERNITE,BORAX,COLMALITE)

Prepare
1) BORAX + HCl 2)Electrolysis KBF4

Properties
1)black non metal
2)semiconductor properties 3)high mp
4)crystal form Icosahedran
5)Boron powder reactive + O2,S,N2,X2
COMPOUND

1)Boron Hydride s(Borane)

Prepare
1)reduction BCl3
2)Hydogenation BCl3

2)Boron Oxide

Prepare1)burn in O2 2)Fusing Solid

3)Boron Hydroxide(Boric Acid)

Prepare
1)Hydrolysis BCl3
2)Na2B4o7+HCl +H2O

4)boron Halide

Prepare Direct with halogen ,High Temperature but BF3 heating B2O3+CaF2@NH4BF4+H2SO4

Stucture : Trigonal Planar ,sp2

5)Boron Nitride

Prepare B2O3+NH3

Form
1)Graphite type(more stable) 2)Diamond type

Electric insulator (localized )

(B)ALUMINIUM

1)Bayer Process  ,Bauxite

Dissolution processBauxite+NaOH,
seeding process Al(OH)3,
heating process

2)Hall-Heroult Process (AlO3 dissolved in molten cryolite Na3AlF6),Graphite electrodes,900C)

COMPOUND

1)OXIDES  Al(OH)4, 450c-> gamma alumina,>1000c ->alpha alumina

Prepare Bayer Process (heating Al(OH)4)

2)HYDROXIDES,nature as Gibbsite

Prepare
1)Ammonium Hydroxide+Al3+ 2)aluminate+CO2

3)HALIDE

AlCl3-dimeric

AlF4-monomeric –not behave as lewis acid,prepare Al+F2

4)ALUM-double sulphate(monovalent,trivalent metal)

# data[].attributes.body
heating Thank you  Dr for today class.Here is my summary for group IIIA

1-GENERAL PROPERTIES
-Electronegativity(Ga>Al) Ga has increase nuclear charge due to poor shielding 3d electron.
2-Trend(B and Al)
-Boron form acidic oxide
-Al form amphoteric oxide
-metallic character increase
3-Preparation Boron
-reaction borax in HCI
-electrolysisKBF4 in mixture of fused KCI and KF at 800 celcius
4-OXIDE(heating in oxygen,thermal decomposition NO3  and OH)
5)HALIDE(direct combination of element,halogenation)
6)HYDRIDE(reduction of BCI3,hydrogenation of BCI3)
7)HYDROXIDE(hydrolysis of BCI3,reaction between dilute HCI and borax)
7)NITRIDE(heating B2O3)IN NH3)
8)DIAGONAL B and Si
-weak acid
-non metal,the hydride are easily vaporized,covalent

-AI(preparation)
-Bayer process(bauxite dissolve in NaOH----precipitation of AI(OH)3--heating AI(OH)3 to form aluminium oxide
-Hall- Heroult process(AI2O3 dissolved in molten cryolite at 900 celcius)
-Chemical properties
-react directly to N2,O2,S
-react with HCI,H2SO4 but not for HNO3)
1-OXIDE(form alfa alumina,gama alumina)
2-HYFRATE
-aluminium hydroxide oxide
3-HALIDE
-ALF3(monomeric)
-soluble in H2O
-AICI3(DIMERIC AI2CI6)
-white solid,covalent)
4-ALUM
-double sulphate(mnovalent,trivalent)
-dissosiate in H2O to form kalium and aliminium
-use in purification water
-arrest the bleeding

# data[].attributes.body
Thank you Dr for today class. Here is my summary for Boron Family
-covalent, metallic and ionic radii increased from B to Tl but for Al and Ga is different as size of Al is more bigger than Ga due to the presence of d orbital in Al that has poor screening effects for the outer electrons
-others show +3 while Tl show +1 due to the inert pair of electron effect
-the enthalpy of hydration is higher except B as B didnt exists as +3 due to the small size so it has high charge density.hence, it has very strong polarization
-metallic increase down the group
-acidity strength decrease down the group as covalent bonds character and electronegativity decreased
-B act as electron acceptor because it is an electron deffiecient--> Lewis Acid
-only form normal oxide( no peroxide and superoxide), can be prepared by heating in oxygen
-Others can form monomer and dimer halides but B only form monomer halides, can be prepared by :
i)direct combination of elements
ii) halogenation of a mixture of oxide and coal
iii) dissolving an oxide/hydroxide/carbonate in HX
ANOMALY OF BORON
-non-metal and form icosahedral,B12(unreactive because bonded strongly)
-B(OH)3 an acid
-monomer
-B cannot replaced H from non oxidizing acid
DIAGONAL RELATIONSHIP OF B AND Si
-hydrides(easily vapourized, covalent, reactive, easily hydrolyzed bye water or acid)
-halides(covalent in nature, easily hydrolyzed in water)
-Boric, silicic acid are weak acid
BORON(kernite, borax, colmanite)
-can be prepared by:
i)reaction of borax in HCl
ii) electrolysis KBF4 compound in a mixture of fused KCl and KF at 800°C
-application of B are neutron absorber( B alloy), cancer treatment, high bormbardent steel in construction
•Boron Hydrides(Borane)
- can be prepared by reduction of BCl3 and hydrogenation of BCl3
-properties of diborane extremely reactive, flammable in air with green flame, react vigorously in acid and Cl2 and fast hydrolysis in water or alcohol
-application of boron hydrides are reducing agent for aldehyde or ketone to alcohol(NaBH4) and supply H2
•Boron Oxide
-can be prepared by burning B in oxygen and fusing solid boric acid
-their properties are react slowly in water, fused with other metal oxide form coloured borate glass
-application of boron oxide is produced borosilicate glass(Pyrex)
•Boron Hydroxide(planar unit that connected by H bond)
-preparation:
i) hydrolysis of BCl3
ii) reaction between dilute HCl and borax
-properties:
i) easily vapourized
ii) acting as Lewis acid(accept OH ion)
iii) weak monobasic acid
iv) stronger acid in diol(glycol, mannitol)
v) antibacterial addictive
•Boron Halides(sp² hybridization)
-preparation :
i) direct halogenation of B with halogen at hight temperature
-properties:
i) covalent and easily vaporize
ii) strong lewis acid but for BF3 is weak Lewis acid due to high electronegativty of F and BI3 is less than BBr3 due to the stearic effect
•Boron Nitrides
-preparation:
i) heating B2O3 in NH3 at 1200°C
-form 2 stable polymorphs( graphite and diamond type) but graphite more stable than diamond due to the Van der Waals forces
-properties:
i) electric insulator as no electron delocalized due to the charge separation on adjacent atom
ii)slippery so used as lubricant
-Borazine can be prepared by reaction between diborane and ammonia( look like benzene but differe and their propertis also differ due to electron in borazine is localised but in benzene is delocalised)
ALUMINIUM(most abundant in earth'crust)
-preparation divided by 2 process which is Bayer Process and Hall-Heroult Process
-Bayer Process has 3 stage which start by dissolution of bauxite by react bauxite with NaOH to produce aluminate ion and dismiss the red mud, then the aluminate ion seeded with crystals to precipitate Al(OH)3.Lastly, heating Al(OH)3 to produce Al2O3( at 600°C, gamma alumina and at 1200°C, alpha alumina) but alumina is solid so melt alumina to form molten alumina
-Continue with Hall-Heroult Process which is electrolysis of molten alumina to produce Al
-chemical properties of aluminium
i) react directly with oxygen, nitrogen, sulfur and halogen at high temperature
ii) do not react with HNO3 since HNO3 is oxidizing agent(oxidise form oxide layer on the Al surface)
iii)react with base form aluminate ion and hydrogen gas
-uses are catalyst for dehydration of alcohol to alkene(Al powder), wrapper, moldibg alloy, tranport(engine component etc)
-Germ stones(fusing alumina with other metal oxides)
•Aluminium Hydrate
- alpha aluminium hydrate(diaspore) for germ stones uses
-gamma aluminium hydrate( boehmite) used for inexpensive flame retardant addictive
•Aluminium Hydoxide(naturally occur as Gibbsite)
-prepared by addition of NH4OH into Al ion solution and acidification of aluminate solution with CO2
-application: as mordant and coagulating agent
•Aluminium Halide
-AlF3(monomeric)
ionic solid since F is very electronegativity, does not behave as Lewis acid(due to electronegativity of F)
•Alum(due to double sulphate of monovalent and trivalent metal ion)
-potash alum- soluble in water to form ion K, Al and SO4²- and use in purification of water, to stop the bleeding wound(medical)

# data[].attributes.body
Summary Group IIIA

~ covalent, metallic, ionic radii increase down the group
~electronegativity Ga > Al ; nuclear charges of 4p increase

Chemical Properties
- B form acidic oxides, Al form amphoteric oxides.
- B form polymeric oxide structure
- B : flammable, gaseous hydrides
- Aluminium hydride : solid
- B : electron deficient, making compounds Lewis acids

General Properties
- B : cannot expand valence electron ( incomplete shielding in s shell )
- All elemet +3 valency except TI +1 ( inert pair electron effect )
- ionization energy high
- form hydrated M(H20)6^3+ except B
- B does not exist in discrete B3+
- metallic character increases
- B & Al not reactive

Anomaly Boron
- non metal, formed icosahedron
- Boron chloride ; monomer
- B doesnt replaced H in oxidizing acid

Diagonal Relationship ( B & Si )
- non metals element
- hydrides easily vapourized
- halides ; covalent
- boric / silicic acid ; weak acid
- oxides ; covalent acid & polymeric macromolecules

Boron
~ preparation : reaction of borax in HCl & electrolysis KBF4

1) Boron Hydrides (Borane)
- reduction boron trichloride
- hydrogenation of BCl3
- diborane (B connected bridging with H2)

2) Boron Oxides
- burning oxygen
- fusing solid boric acid
- produced borosilicate glass(Pyrex)

3) Boron Hydroxide
~ Boric acid
- hydrolysis boron trihalide
- reaction between dilute HCl & borax

~ Borate
- fusing boric acid & metal oxide
- polyoxyborate anion (ring/chain by sharing oxygen)
- Borax ; fusing with transition metal

4) Boron Halide
- direct halogenation of boron with halogen at high temperature

5) Boron Nitride
- heating B2O3 in ammonia at 1200 degree celcius
~ Borazine
- resonance hybrid structure similar to benzene
- reaction between diborane & ammonia

Aluminium
~ preparation : Bayer Process & Hall Heroult Process (Electrolysis Al2O3)

1) Aluminium Oxides
- bayer process
- heating aluminium oxide

2) Aluminium Hydroxide
- addition ammonium hydroxide into Al3+ solution
- acidification aluminate solution with CO2

3) Aluminium Halide
~ industrial
- dry Cl2/HCl over hot metal/molten Al
- reaction between Al and HCl/HBr
- heating aluminium oxide with carbon chlorine

~ laboratory
- hot column reactor of anyhydrous Al2Cl6

4) Alum
- double sulphate of monovalent  and trivalent metal ions

Thankyou Dr for today's explanation about Aluminium.

# data[].attributes.body
Thank you Dr.Sheela for today’s lecture. Here’s my summary:
Group IIIA elements

Exhibit +3 oxidation state and changes to +1 down group; form normal oxides

B-nonmetal, Al-weak metal, Ga-metalloid, In & Ti-metal

Hydroxide: B-acid, Al-amphoteric, others-basic; Halides are dimer except B is monomer

B formed as icosahedral unit of crystal B12; Al form stable oxide layer on surface; both are not reactive

Ga more electronegative than Al: has an increased nuclear charges of 4p  elements due to the presence of their poorly shielding 3d electrons

BORON- preparation: reaction of borax in HCL(90-98%pure), electrolysis KBF4 compound in a mixture of fused KCL & KF (95%pure, at 800 degree Celsius)

properties

electron deficient-> compound Lewis acid;

incomplete shielding of valence electron by 2 e- in s shell-> can’t expand valence shell;

never exist as cation, polarize H2O-> ionization of protons from coordinated water-> aqueous cation is acidic;

limited valence orbitals (2s & 2p)->max coordinate number=4;

reduced water vapour to H at red-hot

diagonal relationship

diagonal relationship with Si: non metals in crystal & amorphous form; has similar size, electronegativity; dissolve in alkali to prosuce H2 & are strong reducing agent in alkaline solution; their oxides are covalent acid and are polymeric macromolecule

hydrides BnHn+4/n+6/n(2-) borane preparation: reduction of BCl3, hydrogenation of BCl3 – gas, toxic, extremely reactive, fast hydrolysis with water/alcohol
oxide(B2O3)
preparation: burning B in O, fusing solid H3BO3- produce borosilicate glass
*soluble in hot water, easily vaporized, weak monobasic acid
hydroxide(B(OH)3) / boric acidB(OH)3, H3BO3
preparation: hydrolysis of BCl3, reaction between dilute HCl & borax
*weak acid in aqueous solution, stronger acid in diol
borate
preparation: fusing boric acid & metal oxide
*coloured glass, Pyrex glass
halide BX3
preparation: direct halogenation of B with halogen(at high temperature)
*covalent, easily vaporized to MW, strong lewis acid
nitride BN
preparation: heating B2O3 in ammonia(t 1200 degree Celsius)
*graphite type, slippery, electric insulator, white refractory solid
borazine B3N3H6
preparation: reaction between diborane and ammonia-reactive towards HCl *reducing agent, sensitive towards moisture, e- is localized

ALUMINIUM- preparation: BAYER process-bauxite dissolved in NaOH->precipitation of Al(OH)3->HEAT  Al(OH3) at 400-600 degree Celsius then 1200 degree Celsius; electrolysis Al2O3 dissolved in molten cryolite(Na3AlF6) at 900degree Celsius with graphite electrodes

readily react with N2, O2, S, halogens at high temperature

oxide(Al2O3) alumina
preparation: Bayer process, heating aluminium hydroxide to gamma alumina(heterogeneous catalyst) to alpha alumina(stable at high temperature, catalyst in dehydration of alcohol to alkene)

alumina hydrate/aluminium oxyhydrate-aluminium hydroxide oxide(AlO.OH); preparation: addition of ammonium hydroxide in Al3+ solution, acidification of aluminate solution with CO2
*as mordant, coagulating agent
aluminium halide(AlX3; dimeric:Al2Cl6) preparation: passing dry Cl2/HCl over hot/molten Al metal, reaction between Al & HCl/HBr, heating aluminium oxide with C + Cl
*dissociate into monomer btwn 400-799degree Celsius and complete at 800
alum M’SO4.M’’2(SO4)3.24H2O
M’=GIA metals ions except Li+, M’’=GIIIA metals ions; potash alum: common alum KAI(SO4)2.12H2O
*use as purification of water, as styptic to arrest bleeding

# data[].attributes.body
Thank you for today's lecture, dr. Below is my summary of Group IIIA, Boron, & Aluminum.

- 1st group to span the dividing line between metals & nonmetals, so it's chemistry is more diverse.
- No definite electronegativity trend, but Ga is more electronegative than Al as Ga has increased nuclear charge.
- Covalent, metallic, & ionic radii increases down the group.
- All elements show stable valency of +3, except Tl=+1 due to inert pair electron effect.
- Metallic character increases down the group (B=nonmetal->In&Tl=metal).
- Only form normal oxide, M2O3. Preparation by heating in oxygen or thermal decomposition of nitrate or hydroxide.
- Thermal stability of the oxides decreases down the group.
- Covalent, dimer, vapour. Preparation by direct combination of elements, halogenation of a mixture of oxide & coal, or dissolving an oxide/hydroxide/carbonate in HX.

1. Boron
- Symbol B, 1s(2) 2s(2) 2p(1).
- Forms acidic oxides B2O3.
- Forms polymeric oxide structure.
- Forms flammable, gaseous hydrides.
- Is electron deicient & making all its neutral compounds Lewis acids.
- Cannot expand valence electron due to the incomplete shielding of the valence shell electron by the 2e in the s shell.
- Icosahedral unit of crystal, B12.
- In halides, only forms monomer, covalent, vapour.
- Does not replace H from non oxidizing acid.
- Diagonal relationship of B & Si; the hydrides are easily vapourized, covalent, reactive, easily hydrolyzed by water/acid, halides are covalent, boric/silicic acids are weak acids, non-metal elements, oxides are covalent acids, polymeric macromolecules.
- Preparation of Boron by reacting borax in HCL or electrolysis KBF4.
- Compounds of Boron; hydride, oxide, hydroxide, halide, nitride.
- Structure of diborane is an electron deficient structure (bridging-H).

2. Aluminum
- Symbol Al, 1s(2) 2s(2) 2p(6) 3s(2) 3p(1).
- Forms amphoteric oxide, Al2O3.
- Forms stable oxide layer on its surface
- Preparation by Bayer proceses (chemical process) & Hall-Heroult Process (electrolysis).
- Bayer Process: bauxite is dissolved in NaOH (to seperate red mud) -> precipitation of Al(OH)4 using crystal seeds of hydrated aluminum hydroxide -> heating aluminum hydroxide to obtain pure aluminum oxide.
- Hall-Heroult Process: Al2O3 is dissolved in molten cryolite (Na3AlF6=reduce melting point, solvent, current carrier). Cathode= Al3+ + 3e- -> Al, anode= 2O2- -> O2 + 4e-, electrode= graphite.
- React directly with O2, N2, S, & halogen on heating at high temperature.
- Alpha-alumina & gamma-alumina.
- Compounds of Aluminum; aluminum hydrate, hydroxide, halide.

# data[].attributes.body
Thank you Dr for today class

Summary for Group IIIA :
- Boron forms acidic oxides and aluminium can form amphoteric oxide.
- Boron is different form other element due to incomplete shielding effect
- Metallic character increases down the group.
- B and Al not reactive because B formed icosahedral while Al form stable oxide layer on its surface

Boron
- Preparation is by reaction of borax in HCl and electrolysis KBF4.
- Boron powder extremely reactive , reacts with O2, S, N2 and X2
- Boron Hydrides: * known as borane
* diborane is toxic and extremely reactive , flammable in air with green flame
* diborone electron deficient structure : bridging-
- Boron oxide   : * acidic oxide
* Produced borosilicate glass
- Boron Hydroxide :* known as Boric acid
* soluble in hot water
* white needle crystal
* weak acid in aq solution but becomes stronger acid in diol
-Boron Halide  : *Trigonal planar with B having Sp2 hydridization

Aluminium
- Most abundance element in earth crust
- Preparation using 2 processes Bayer Process and Hall-Heroult process
- reacts directly with O2, N2, S and halogen
- uses in transport , construction and electrical

# data[].attributes.body
Thank you Dr for the class today. Here is my summary for group IIIA

General properties
- B forms acidic oxides while Al forms amphoteric oxide
- B forms polymeric structure
- All elements show stable valency of +3 except Ti
- Metallic character increases down the group
- All elements form normal oxide

Anomaly of B
- non metal and form B12
- does not replace H from non oxidizing acid

Diagonal relationship of B an Si
- hydrides are easily vapourized
- halides - covalent
- non metal elements

Boron
- preparation of borax in HCl and electrolysis of KBF4
- properties : non metal element, high melting point, red hot boron reduced water vapour to hydrogen

Boron Hydride (borane)
- preparation by  hydrogenation of BCl3
-properties of B2H6 : toxic gas, extremely reactive, very soluble in H2O

Boron Oxide
- prepared by burning B in O2
- properties : acidic, react slowly in H2O

Boron Hydroxide (Boric Acid)
- prepared by hydrolysis of boron trihalide
- properties : white needle crystal, soluble in hot H2O

Boron Halide
- prepared by direct halogenation of B with halogen
- lewis acid : BF3 < BCl3 < BBr3 > BI3
-react vigorously with H2O

Boron Nitride
- prepared by heating B2O3 in NH3
- properties : graphite type, electric insulator

Borazine
- prepared through reaction between diborane and NH3
- properties : liquid at room temperature

Aluminium
- prepared by Bayer process and Hall -Heroult process
- chemical properties : react directly with O2, N2, Sand halogen at high temp.
- uses : aluminium powder, as wrappers

Aluminium Oxide
- prepared through Bayer process
- uses : as refractory, as stationary phase in column chromatography

Aluminium Hydroxide
- prepared form addition of NH4OH and acidification of aluminate solution
- properties : white solid
- as mordant and coagulating agent

Aluminium Halide
- prepared by reaction between Al and HCl
- physical properties : white solid

Potash Alum
- colourless hexagonal crystal
- soluble in H2O
- as purification of H2O

# data[].attributes.body
Thank you for today's lesson dr. Here is my summary based on the group IIIA

Summary Group IIIA

Physical Properties
Boron (Metalloids) - good conductor at high temperature only
Al, Ga, Ti (Metals) - good conductor, soft/malleable

General Properties
- exhibit as +3 oxidation
- covalent, metallic and ionic radii increases
- Ga more electronegative than Al due to alternative effect

BORON
- Boron is different due to it cannot expand the valence shell
due to incomplete shielding
- The IE is very high to remove 3 valence electron
- Not exist as discrete B3+ due to very high charge density

COMPLEXION of IONS
Al3+ ---> Ti3+
- can expand from 4 to 6 due to it can expand it
valence sehell in d orbital

B can only form up to 4 due to limited valence orbitals

OXIDES
- B2O3 (acidic)
Al2O3 (amphoteric)
Ti2O3 (basic)
- thermal stability decreases

Preparation
- heating in oxygen
- thermal decomposition of nitrate/hydroxide

HALIDES
B - monomer
Others -covalent,dimer

Preparation
- direct combustion, halogenation oxide and coal,
dissolving oxide in HX

Anomaly of Boron
- formed icosahedron, doesnt replaced H from non oxidiing acid

Diagonal Relationship (Si)
- Hydrides - easily vapourized, covalent, reactive, easily hydrolyzed
- Halides - covalent
- Boric acids - weak acid
- non metal
- oxides - covalent acid, polymeric macromolecules

BORON
Preparation
- Borax in HCl, electrolysis KBF4
Properties
- high melting point, crystal form (very stable)

COMPOUNDS OF BORON
Boron Hydrides (Borane)
preparation - reduction and hydrogenation BCl3
properties - exist as gas, toxic, extremely reactive,
fast hydrolysis in water, react vigorously in HCl
electron deficient structure - B connected by bridging hydrogen
NaBH4 as reducing agent, supply of H2 gas

Boron Oxides
preparation - Burn B in O2, fusing solid boric acid
application = Borosilicate glass

Boron Hydroxides (Boric)
preparation - hydrolysis BCl3, reaction with dilute HCl
properties - easily vapourized, weak monobasic acid, react with alcohol
to form borate ester, strong acid in diol

Borate
Prepared by fusing boric acid and metal oxide

Borax
- a borate species
- use as coloured glass/pyrex glass

Boron Halides
- halogenation at high temperature
properties - covalent and easily vapourize, strong lewis acid

Boron Nitride
preparation - Heating B2O3 in NH3
properties - form planar hexagon layer, slippery (used as lubricant)
electric conductor, white refractory solid

Borazine
preparation - diborane + ammonia
properties - liquid at room temp. , similar structure as benzene,
different propeties due to pi electron in borazine is localized

ALLUMINIUM
preparation - bayer process, hall-heralt process
Chem. properties
- react directly with O2, N2, S and halogen
- react with HCl,H2SO4,base
- not react with HNO3
uses - aluminium powder, to prepare alloy, wrapper,electrical cable

COMPOUNDS
Oxides
form-alpha and gamma alumina
preparration - bayer process, heating aluminium hydroxide
application
- alpha alumina very stable at high temp.
used as refractory, acid adn hydration resistent
- gamma alumina
as catalyst, stationary phase in column chromatography
- used as support for transition metal, germ stones

Hydroxides
AlO.OH (aluminium oxyhydroxide)

Aluminium Hydoxides
preparation - addition NH4OH into Al3+, acidification of
aluminate with CO2
properties - white solid (amphoteric)
Application - as morder, coagulating agent

Halides
AlF3 exists as monomeric
- ionic solid, soluble in water, form salt with group IA,
not behave as lewis acid

AlCl3
exist also as dimeric
preparation - passing dry HCl with hot molten Al, reation Al and HCl,
heationg aluminium oxide with C and Cl, using hot column reactor
for preparation of anhydrous Al2Cl6 (easily hydrolyzed in moist air)
properties - white solid, covalent in nature, sublimes at 180c,
exist as dimer up to 400c

Alum (sulphate)
double sulphates (monovalent, trovalent)
Potash Alum - colourless hexagonal crystal, soluble in water,
hydrolyze in water to acidic solution
used as - purification of water, as mordant in dyeing, for tanning leather

# data[].attributes.body
Thank you Dr for the class just now. Here is my summary for group IIIA. In group IIIA, we learned:

-EN of group IIIA elements
-metal oxide / halide
-Anamoly of B
-5 diagonal relationship between B and Si

Boron:
- preparation of borax in HCL and electrolysis of KBF4
- properties of Boron eg B12 is extremely chemically inert, red hot boron dissolve in water to produce B2O3

Boron Hydride(borane)
- preparation by reduction of boron trichloride and hydrogenation of bcl3
- properties of B2H6 : toxic gas, extremely reactive, very soluble in water/alcohol

Boron hydroxide / oxide
- preparation
- properties

Boron halide:
- preparation
-  lewis acid : BF3 < BCl3 < BBR3 > BI3
- react vigorously with H2O

Boron Nitrate
type: graphite / diamond type
- Borazine is totally different from benzene although both have similar shape

Alumuniun
- preparation
- chemical properties
- uses

Alumunium oxide
- preparation from bayer process
- application

Aluminium Hydrite - Hydroxide
- preparation from addition of NH4OH or acidification of aluminate solution
- properties
- application

Alumunium Halide
- monomeric
- lewis acid and base
- industry / lab preparation

# data[].attributes.body
Thank you Dr for today's class. Here some summary for group IIIA;
General properties
• Boron forms acidic oxides while Al forms amphoteric oxide
• B form flammable, gaseous hydride while aluminum hydride is a solid
• Elements in group IIIA show stable balency of +3 except TI
• metallic character increases down the group
• strengt of acidity decreases down the group due to;
- decreases in electronegativity
- decreases in covalent bonds
Boron
•  anomaly of B;
- nonmetal and formed icosahedron
- does not replaced H from non oxidizing acid
• diagonal relationship B and Si
- hydride are easily vaporized
- nonmetal element
- covalent acid
• preparation of B
- react with HCL
- elctrolysis KBF4
~ Compounds of B
• boron hydride (borane)
-  Preparation:
- reduction of BCL3
- hydrogenation of BCL3
• boron oxide
- acidic oxide
- produce coloured borate glads by fused with other metal
• boron hydroxide (boric acid)
- preparation;
- hydrolysis BCL3
- reaction between HCL and borax
- weak acid in aqueous silution but stronger acid in diol
• borate
- prepared by fusing boric acid and metal oxide
• boron halide
- preparation: direct halogenation at high temp.
• boron nitride
- preparation;
- heating B2O4 in ammonia
- form 2 stable polymorphs
• borazine
- structure similar with benzene
Aluminium
• preparation:
- Bayer process
- Hall- Heroult process
~ Compounds of aluminum
• oxide
- form: alpha and gamma alumina
- preparation: bayer process and heating AL(OH)3
• aluminum hydrate (aluminum oxyhydroxide)
- also exist in alpha n gamma form
• aluminum hydroxide
- naturally as gibbsite
- preparation:
- addition of NH4OH
- acidification of AL(OH)4 in CO2
• aluminum halide
AlF3
- soluble in water
- does not behave as Lewis acid
• alum
- name given to double sulphate of monovalent and trivalent metal ions

# data[].attributes.body
Thank you dr for today's class.
for group IIIA summary:

1) Boron cannot expand it shell because boron does not have d orbital
2) metallic character down the group is increase
3)other element except boron can expand the coordination number until 6+
4) group IIIA can only form normal oxide
5)boron is the anomlay elements in the group and have diagonal relationship with Silicon
6) Boron can form boron hydride (diborane), boron oxide, boroh hydroxide,boron halide and boron nitride (borazine)
7) Aluminium can be prepared industrially by bayer process and hall-heroult process
8) aluminium oxide can form to type, alpha and gama alumina
9) aluminium can form aluminium oxide(alumina), aluminium hydrate(oxyhydroxide), aluminium hydroxide, aluminium halide(not behave as lewis acid and form dimer structure).

thank you dr and have a nice day !

# data[].attributes.body
Thank you Dr for today’s lesson and one pre-recorded class. For now, this is my  summary for group IIIA:

- Covalent, metallic & ionic radii increases from B to Ti

- Why Ga is more electronegative than Al; due to their poorly shielding 3d electrons.

- B is different because of it cannot expand valence shell and also forms icosahedral unit of crystal which is very stable

- B is electron deficient and making all its neutral compounds Lewis Acids

- Diagonal relationship of B & Si

- Preparation; reaction of borax in HCl & electrolysis KBF4

- Diborane structure; bridging-H (B-H-B)

- Boric acid structure; planar unit & each layer hold by van der Waals forces and

forms 2 dimension as hexagon

- Boron Halide structure; trigonal planar with sp2 hybridization

- Preparation of Al2O3; Bayer Process (3 steps) (obtain pure alpha-alumina & gamma-alumina)

& Hall-Heroult process (Electrolysis of Al2O3)

- Do not react with HNO3 (HNO3 is oxidizing acid)

- Aluminium oxyhydroxide, AlO.OH  exist in 2 forms; alpha-AlO.OH (diaspore) & gamma-AlO.OH (boehmite)

- Al(OH)3 – Gibbsite

- AlX3 – not behaves as Lewis Acid; F is very electronegative

- Alum (monovalent & trivalent metal ions)

- Potash alum (KAI(SO4)2.12H2O) use as purification of water

# data[].attributes.body
Thankyou dr for today's and the previous lesson.The summary  for group IIIA is,
-Group IIIA includes the metalloid boron (B), as well as the metals aluminum (Al), gallium (Ga), indium (In), and thallium (Tl)
-Boron mostly form covalent bond
-The valence electron of group IIIA is (ns2np1)
-Boron and aluminium have  noble gas core
-Boron is classified as a metalloid, having properties of both metals and nonmetals
-Ga is more electronegative than Al because Ga has increase nuclear charge of the 4p elements
-Boron forms acidic oxides while Al forms amphoteric  oxides
-element show stable valency +3 except for Tl  is +1 due to inert effect
-Metallic character increase by down the group
-Al can be prepared by bayer process and hall-heroult process
-Al can form aluminium oxide,aluminium hydride,aluminium hydroxide,aluminium halide
-Aluminium oxide can form alpha and gama alumina

# data[].attributes.body
Thankyou for today.s lesson dr.
Summary for grouo IIIA:
-group IIIA are the first group to span the dividing lune between metal and non-metal , so its chemistry is more divere than that of group IA & II,
-covalent, metallic and ionic radii increases from B to TI.
-Ga is more electro-ve than AI bcs Ga has increased nuclear charges of 4p elements due to the presence of poorly shielding 3d e-.
-Boron formms acidic oxides & aluminium forms amphoteric oxide.
-Boron form flammable, gaseous hydrides & aluminium is a solid
-Boron is e- deficient and making all its neutral compunds lewis acid.
- Boron cant expand valence e-
-All element show stable valency of +3mexcept TI.
-IE very high to remove all 3 valence e-
-metallic character increases down the group
-B &AI seem not reactive.
-acidity decreases down the group.
-oxides can be repared by heating in oxygen or thermal decomposition of nitrate or hydroxide.
-thermal stability of oxide decreases down the group.
ANOMALY BORON
- nonmetal, formed icosahedron
-does not replace H from non oxidizing acid.
DIAGONAL RELATIONSHIP B&Si
- hydrides are easily vapourized, covalent, reactive, easily hydrolyzed by water or acid
-halides- covalent in nature
-boric acids- weak acid
-non-metal elements
-B2O3/SIO2 (oxides)- covalent acid, polymeric macromolecules
- preparation of boron has 2 , reaction of borax in HCL and electrolysis KBF4
-compund of boron has born oxide, boron hydroxide, borate , boron halide, boron nitrade and borazine.
ALUMINIUM
- most abundant element in earth curst.
-preparation using 2 process : BAYER POCESS & HALL-HEROULT PROCESS
- Al compunds has oxide, aluinium Hydrate, aluminium Hydroxide, aluminium Halide. alum and potash Alum.
-structure of AI2CI6 dimer . almost the same with B2H6

# data[].attributes.body
Thank you dr for the synchronous class today. I learned a lot of new things today and here is my summary about this topic.
1. Anamoly of Boron
-Boron is non metal
-Boron oxide is acidic
-Boron hydroxide is an acid
-Boron chloride is a covalent monomer
-Boron does not replace H from non oxidizing acid
2. Diagonal relationship (B&Si)
-hydrides easily vapourized, covalent, easily hydrolized by water or acid
-halides are covalent and easily hydrolysed by water
-acids are weak acid
-non metal elements
-oxides form covalent acid and polymeric macromolecules.
3. Preparation of Boron
-Reaction of borax in HCl
-Electrolysis KBF4
4. Compounds of Boron
Boron hydrides(borane)
-properties based on diborane
-electron deficient structure (bridging-H)
-sp3 hybridization
-BH₄⁻ ion is reducing agent for aldehyde/ketone to alcohol
-supply of H2 gas
Boron oxide (B2O3)
-Preparation

burning B in oxygen

fusing solid boric acid

-Properties: acidic oxide
-Produce borosillicate glass
Boron Hydroxide (boric acid)
-Preparation

Hydrolysis of boron trihalide

Reaction betw dilute HCl and borax

-Properties: easily vapourized, weak monobasic acid, Lewis acid, react with alcohol to form borate ester.
-Weak acid in aq soln but strong acid in diol
-Thermal dissociation of H3BO3 formed metaboric acid (HBO2)
-Act as antibacterial additive
-Each unit is connected by H- bond. Each layer hold by van der Waals forces.
Boron Halide (BX3)
-Preparation

Direct halogenation of boron with halogen at high temp

-Trigonal planar with B having sp2 hybridization
-Properties

Covalent and easliy vaporize (inversely proportional to MW)

Strong Lewis acid

***BF3 is weak Lewis acid
high electronegativity of F, lone pair e- from F is donated back to B, forming p pi-p pi bond between B-F bond, electron density increases, weak Lewis acid.

- Used as Friedel Crafts catalysts in olefin polymerization of alkylation of aromatic-HC
Boron Nitride
-Preparation

Heating B2O3 in ammonia at 1200 deg celcius

Form 2 stable polymorphs

- Properties

Graphite type: form planar hexagon layer

Electric insulator

Borazine (B3N3H6)
-Resonance hybrid structurre similar to benzene.
-Preparation: reaction between diborane and ammonia
-Properties

Liquid at r.t.p

diff properties with benzene

due to pi electron in borazine is localized but in benzene is delocalized, electronegativity diff betw B-N is large, charge separation

5. Preparation of Aluminium (Industrial)
-2 Processes

BAYER PROCESS

HALL-HEROULT PROCESS

6. Chemical properties of Al
- react with HCl to give H2 gas
- react with H2SO4 to give sulphate and SO2
-DO NOT react with HNO3 due to the formation of an ocide layer on the surface (HNO3- oxidizing acid)
-react with base to give aluminate ion and H2
7. Aluminium Compounds
Aluminium Oxide (Al2O3)
-alpha - alumina

most stable at high temp

catalyst in dehydration of alcohol to alkene

-beta- alumina

powder form

catalyst

as stationary phase (solid) in column

-Preparation

Bayer Process

Heating aluminium hydroxide

Aluminium Hydrate (AlO.OH)
- alpha-AlO.OH (diaspore)

for germstone use

- beta-AlO.OH (boehmite)

inexpensive flame retardant additive

Aluminium Hydroxide (Al(OH)3)

-Gibbsite
-Preparation

Addition of ammonium hydroxide into Al3+ solution

Acidification of aluminate solution with CO2

-Properties

white solid - amphoteric

-As mordant
-Coagulating agent
Aluminium Halide (AlX3)

-AlF3 is monomeric
-Ionic solid
-Soluble in water
-Does not behave as Lewis acid
-AlCl3 (Al2Cl6 is dimeric)

Industrial preparation

Laboratory preparation

Alum
-Double sulphatess of monovalent and a trivalent metsl ions
-Potash alum

colourless hexagonal crystal

soluble in water

hydrolyze in water to form acidic soln

used as purification of water, mordant, tanning leather and sizing paper, medical use as stypytic to arrest the bleeding.

# data[].attributes.body
Summary for group IIIA
-group consist of metals and nonmetal
-covalent, metallic and ionic radii increase from B to Tl
-Ga is more electronegative from AL as Ga has increase nuclear charge in 4p and poor shielding by 3d
-element show stable  valency +3 except for Tl(+1) due to inert effect
metallic character increase down the group
Al and B seem not reactive because Al form stable oxide layer on its surface while B form Icosahedral unit of crystal B12

Acidity decrease down the group due to decreasing electronegativity and covalent bonds character
-form normal oxide
B2O3 -acidic
Al2O3 and Ga2O3 -amphoteric
In2O3 and Tl2O3 -basic
Halide
-B form monomer
other form dimer
_Anomaly of Boron
-nonmetal, form Icosahedron B12
-does not replace H form oxidizing acid
Boron Hydride= Borane
properties(diborane)-exist as gas, toxic, extremely reactive, flammable in air
Boron Oxide
-acidic, react slowly in water
Boron Hydroxide
-act as  Lewis acid-accept OH-
produce Borate ester when react with alcohol
Boron Halide
-covalent and easily vaporize
-strong Lewis acid
Aluminium
-prepared by Bayer Process(obtain Al2O3) and Hall-Heroult process(obtain Al)
-Used as catalyst for dehydration of alcohol, prepare ally, wrapper
-oxide  (Al2O3)
alpha-alumina and gamma- alumina
-Aluminium Hydrate (AlO.OH)
alpha AlO.OH (diaspore)
gamma AlO.OH(boehmite)
-Halide
AlF3(monomeric)
AlCl3(dimeric Al2Cl3)
-Alum(sulphate)

# data[].attributes.body
Thank you dr for today's class.
Summary of group IIIA:
-covalent ionic and metallic radius increasing down the group.
melting and boiling point decreasing down the group.
-electronic configuration ns^2 np^1.
-generally exhibit +3 oxidation state and changes to +1 as the group is descended
-trend on B and Al=
~boron forms acidic oxides and aluminum forms amphoteric oxide
~boron forms polymeric oxide structure
~form flammable,gaseous hydrides,aluminium hydride is a solid
~boron is electron deficient and making all its neutral compounds lewis acids.
-General properties=
~boron is exception for octet rule  as it can have less than 8 electron valance as it cant expend valence shell
~boron never exist as discrete B^3+ or hydrated b(H2O)4^3+ as very high density
~metallic character increase down the group
~B and Al seem not reactive
~acidity decrease down the group
~Al to Ti coordination number can expand from 4 to 6 as they can expend valence shell using d orbital

BORON:
-preparation of boron;
1.reaction of borax in HCl
2.elctrolysis KBF4
-properties;
1.black non-metal element but shining likes metal
2.Semiconductor
3.high melting point
4.crystal form
5at red-hot,it reduced water vapour to hydrogen
-applications;
1.neutron absorber
2.cancer treatment
3.high bombarment steelin construction material.
4.high temperature semiconductor
-boron hydrides;
1.known as borane
2.preparation by reduction boron trichloride and hydrogenation of BCl3.
3.it properties is exist in gas,toxic,extremely reactive,fast hydrolysis in water,react vigorously in acid and Cl2 and have elctron deficient structure which consist of bridging-H
4.reducing agent
-boron oxides;
1.acidic oxides
2.react slowly in water
-boron hydroxide;
1.known as boric acid
2.white needle crystal
3.soluble in hot water
4. weak monobasic acid and easily vapourized
-boron halides;
1.trigononal planar structure
2.covalent and easily vapourized
-boron nitride;
1.form planar hexagon layer
2.electric insulator and white refractory solid

ALUMINUM:
-most abundant element in earth
-preparation =
1st step:Bayer Process=
1.bauxite dissolved in NaOH
2.precipitation of Al(OH)3
3.Heating aluminiumhydroxide to obtain pure aluminum oxide
2nd step:Hall-heroult Process (Electrolysis)=
Al2O3 dissolved in molten cryolite and electrolysis carried out at 900 degree celcius with graphite elctrodes.
-chemical properties:
1.react directly with O2,N2,S and halogen on heating at high teamperature.
2.react with HCl to give H2 gas.
3.React with H2SO4 to give sulphate and SO2
4.do not react with HNO3

# data[].attributes.body
Summary :
1) Group 13 is the first group to span the dividing line between metals and non metals.
2)It has electric configuration of ns1np1.
3)Covalent, metallic, ionic radii increases from B to Ti.
4)Ga is more electronegative than Al as Ga has increase nuclear charges of the 4p elements.
5)Boron forms acidic oxide while Aluminium forms amphoteric oxides.
6)The general properties are such as boron is different from other elements in group because it cannot expand its valence shell.
7)All elements shows valence of +3(except of Ti shows valency of +1) and IE is very high.
8)The strength of acidity decrease down the group due to decrease in electronegativity and in covalent bond character.
9)Group 13 metals forms oxides by heating in oxygen or by thermal decomposition whereas it forms halides by direct combination of elements ,halogenation of mixture oxide and coal, dissolving an oxide.
10)The anomaly of boron are such as non-metal ,boron oxide is an acid, boron chloride is monomer, covalent.
11)The diagonal relationship are such as hydrides are easily vapourised, covalent, easily hydrolysed , halides are covalent, boric/silicic acid are weak acid.
12)Boron is prepared by reaction of borax in HCL.
13)The compound of boron are boron hydrides, boron oxides, boron hydroxide , boron halides, boron nitrate.
14)Aluminium can be prepared by using 2 processes which are bayer process and Hall-Heroult process(Electrolysis of Al2O3).
15)Chemical properties of aluminium such as reacts with O2,N2,S,halogens, reacts with HCl to give H2 gas, reacts with H2SO4.
16)Aluminium compounds are such as aluminium oxide, aluminium hydrate ,aluminium  halide, and also alum.
17)Potash alum are colourless hexagonal crystal, soluble in water to form k+,Al3+, hydrolyzes in water to acidic solution.

Thank you dr for the two lectures on group 13. Will be looking forward to do tutorial questions :)

# data[].attributes.body
Thank you Dr. for today's lesson and recorded video . I have learnt about group IIIA and I need some time to understand about it . Here are my summary about Group III A :-
- Group IIIA has a diverse chemistry due to the dividing line between metals and non- metals.
- As we going down the group , oxidation state of +3 changes to +1 . Covalent ,metallic and ionic radii increase.
- Ga is more electronegative than Al.
- Trends for Boron and Aluminum as
---Boron can forms acidic oxides , polymeric oxide structure , flammable , gaseous hydrides.
--- Aluminium can forms amphoteric oxide , aluminium hydride as a solid.
- Boron is different as it cannot expand valance shell due to incomplete shielding effect
-Boron never exist as discrete B3+ or hydrated B(H2O)4^3+ due to high charge density
- Boron and Aluminum seem not reactive due to B formed as icosahedral unit of crystal and Al form stable oxide layer on its surface.
- Anomaly of Boron where boron is non- metal, can formed icosahedron  , acidic compound and does not replace H from non oxidizing acid .
- Dioganal relationship of B with Si such as both hydrides are easily vapourized , covalent in nature ,reactive and easily hydrolyzed by water .Both are weak acids and non-metal elements.
- Boron can be exists in kernite , borax and colmanite. There are 2 ways to prepare Boron which are reaction of borax in HCl and electrolysis KBF4 . Some of properties of boron are boron is a black non-metal but shining like metal and have high melting point . The applications of boron are act as neutron absober , used for cancer treatment and as high temperature semiconductor .
- Properies , preparation , stuture and application of hydrides ,oxide, hydroxide, halide and nitride of boron and aluminium.
- Aluminium can be prepared by using 2 process which are Bayer process and Hall-Heroult process.
- Chemical properties of aluminium such as aluminium can react directly with O2 , N2 , S and halogen at high temperature.
-Some of uses of aluminium are as wrappers , to prepare alloy and act as catalyst .

# data[].attributes.body
Thankyou Dr for your explanation.
Summary for Group IIIA :

BORON
-From B to Tl covalent ,metallic and ionic radii increases.
-Down the group, electronegative increases except Al.
-All electron shows valency electron +3 but Tl shows +1 due to inert pair electron effect.
-B and Al not reactive because B form isocahedron while Al form stable oxide layer.
-Down the group, strength of acidity decreases.
-All element of oxide form normal oxide and thermal stability of oxide decrease down the group.
-Boron is non metal, form covalent and does not replcae H from oxidizing acid.
-B(OH)3 is weak acid in aqueous but stronger in diol.
-Borazine have similar structure like benzene but have different properties such as borazine is localized while benzene can be delocalized.

ALUMINIUM
-Aluminium most abundent element in earth crust.
-Important source of aluminium is bauxite.
-Preparation of aluminium using 2 process: Bayer Process and Hall-Heroult Process.
-Aluminium oxide form alpha and gamma alumina.
-Lewis acid can act as electron acceptor while lewis base is a species that donate electron pair.

# data[].attributes.body
Thank you dr for today lecture.
Here summary for group IIIA:
Trends
-covalent, metallic and ionic radii increases from B to Ti
General properties
-B is different bcs cannot expand valence shell electron.
-Show stable valency +3 (except Tl)
-IE very high
-B never exit as discrete B3+ or hydrated
ANOMALY OF B
-non metal
-oxide - acidic
-hydroxide - acid
-chloride - covalent
-does not replaced H
Diagonal relationship (B&Si)
-hydrides easily vapourizes,covalent,reactive,easily hydrolyzed by water or acid
-halides - covalent
-boric/silicic acid- weak acid
-non metal
-oxides - covalent acid
BORON
-prepared by reaction of borax in HCL, electrolysis KBF4
ALUMINIUM
-most abundant element
-as boxite ores , cryolite (sources of al)
-prepared by bayer process (3 step), hall-heroult process.

# data[].attributes.body
Thank you Dr for today's class.The summary for Aluminium is:

1. There are 2 ways to prepare aluminium which is by Bayer Process (chemical process) and Hall-Heroult Process (electrolysis of Al2O3)

2. Chemical properties of aluminium is:
- react directly with oxygen, nitrogen, sulphur and halogen at high temperature.
- react with hydrochloric acid to form hydrogen gas.
- react with sulphuric acid to give sulphate and sulphur dioxide.
- react with base to give aluminate ion and hydrogen gas
* does not react with nitrate acid due to the formation of an oxide layer on the surface. nitrate acid is an oxidizing acid.

3. Uses of aluminium:
- aluminium powder used as a catalyst for dehydration of alcohol to olefin.
- to prepare alloy with Cu,Mg,Si etc.
- as wrappers/food container.
- in transport such as engine component of cars, space shuttle
- in construction building such as window frames.

4. Aluminium compounds:
i)oxide
- Forms alpha alumina and gama alumina
- can be prepared by Bayer Process or heating aluminium hydroxide.
ii)hydrate---hydroxide
- hydrate exist in 2 forms which are alpha (diaspore) and gama (boehmite)
- hydroxide ( occurs naturally as Gibbsite)
- prepared by addition of ammonium hydroxide into Al3+ solution or acidification of aluminate solution with CO2.
iii)halide
- AlF3 (monomeric) does not behave as Lewis acid.
- AlCl3 can be prepared by passing dry Cl2/HCl over hot Al metal/molten Al or reaction between Al and HCl/HBr or heating aluminium oxide with carbon and chlorine.

# data[].attributes.body
Thankyou Dr for your today's explanation . Here are my some summary :
-Ionic radii increases down the group 3
-But electronegativity Ga is more than Al due to presence of poorly effect on 3d orbital of Ga
-Boron form acidic oxides , form flammable
-Boron is electron deficient and making neutral compound lewis acid
-Aluminum form amphoteric oxides
-Boron is differ from other group because it cannot expand the valence electron shell and incomplete shielding
-IE is very high to remove 3 electron
-Boron and Aluminium does not reactive because
o Boron form icosehedral unit crystal
o Aluminium form stable oxide layer of icosehedral unit
DIAGONAL RELATIONSHIP B&Si
-The hydrides are easily vaporized
-easily hydrolysed by water
-its a weak acid
-its non metal element
-Boron oxides and Silikon Oxides will form covalent acid
PREPARATION OF BORON
-Reaction of borax in HCL
-Electrolysis KBF4
PROPERTIES
-Black non metal element but shining
-Semiconductor properties
-High melting point
OXIDES
-Preparation :
o Heating in oxygen
o Thermal decomposition of nitrate or hydroxide
HALIDES
-Preparation :
o Direct combination of element
o Halogenation
o Dissolving an oxide
OXIDES
-Preparation :
o Burning Boron in oxygen
o Fusing solid
HYDROXIDE
-Preparation :
o Hydrolysis of boron tri halide
o Reaction between dilute HCL and borax
HALIDE
o Preparation :
-Direct halogenation of boron
TREND LEWIS STRENGTH
BF3<BCl3<BBr3>BI3
ALUMINIUM
-OXIDES
-Form alpha alumina or beta alumina
-Preparation :
1. Bayer process
-bauxite disssolve in NaOH
-Precipitation of Alumina hydroxide from concentrated alumina hydroxide
-Heating Aluminium hydroxide
2. Hall-Heroult process
-dissolve in molten cryolite
-OXIDES
-Form alpha alumina or beta alumina
HYDROXIDES
-Preparation :
-Addition of ammonium hydroxide into Al3+ solution
-Acidification of aluminate
HALIDES
-Exist in monomeric compound
-Preparation :
-Passing dry Cl2 over hot metal
-Reaction between Al and HCl
-Heating aluminium oxide with carbon and chloride

Dr, I want to ask , whats the phase of Al(p) ? Is the p refer to pure as solid or something else ?

# data[].attributes.body
First of all, I’m sorry Dr that my voice is too slow due to  my mic problem huhu. Thank you for today’s lesson Dr. I will do the summary of what should I explain just now.

Why BF3 is a weak Lewis acid
- electronegativity of F is very high
- lone pair electron from F donated back to B, forming p(pi)-p(pi) bonding between B-F bond
- Hence, electron density increases on B.
- Thus, it forms weak Lewis acid.

# data[].attributes.body
Thank you dr for Group IIIA teaching and explanation.

Summary:
1) anomalies of B:
- form acidic oxide and hydroxide.
- has only maximum coordinated number of 4.
- form covalent monomer halides.
- form flammable, gaseous hydrides.
- cannot expand valence shell.
- crystal form is icosahedron B12.

2) Diagonal Relationship between B and Si

3)special properties, preparation and application of B and Al and their compounds.

4) Lewis acidity decrease down the group due to decrease in electronegativity and covalent bond charcter.

# data[].attributes.body
Summary Group IIIA
- Has a diverse chemistry because has dividing line between metals and nonmetals
- Stability of +3 decreases down the group due to inert pair effect
- Ionic radii increases down the group
- Electronegativity: Ga > Al, increased nuclear charges of 4p (poor shielding of 3d e-)
- B -> acidic oxide, Al -> amphoteric oxide
- B -> polymeric oxide structure, flammable gaseous hydrides (Al -> solid hydride), all neutral compound is Lewis acid (electron deficient)
- B is anomaly (can't expand valence shell)
- Very high IE & hydration energy
- B never exist as B³⁺ (high charge density)
- Metallic character increases down the group
- B & Al seem unreactive (B - icosahedral crystal, Al - oxide layer)
- Lewis acidity: decreases down the group ( decrease electronegativity & covalent bonds)
- Complexation: uses d orbital (B exception)

Oxides
- all normal, changes from acidic to basic
- Prep: heat in O₂, thermal decomposition (thermal stab. decreases)

Halides
- all dimer except B
- Prep: direct comb., halogenation, dissolving in HX

Anomaly of B
- non metal, acidic oxide & hydroxide, monomer halide, doesn't replace H of non oxidizing acid

Diagonal Relationship
- Hydrides : easy vaporized, covalent, reactive, easy hydrolyzed
- Halides: covalent
- Acids: weak
- Nonmetal
- Oxides: covalent, polymeric, macro

Boron
- Prep: Borax in HCl, electrolysis KBF₄
- nonmetal but shines, semiconductor, high mp, icosahedron crystal, very reactive powder, red-hot reduces water vapour to H₂
- App.: neutron absorber, cancer treatment, construction material, semiconductor
Hydrides
- Borane
- Prep: reduc. BCl₃, hydrogenation
- gas, toxic, reactive (green flame), fast hydrolysis, react vigorously with acid
- Diborane: e⁻ deficient (bridging H - dimer form), sp³
- App.: NaBH₄ - reducing agent, H₂ supply
Oxide
- Prep.: Burn in air, fuse solid boric acid
- acidic, react slowly with H₂O, colors glass
Hydroxide
- aka. Boric
- Prep.: hydrolysis, react with HCl and H₂O
- white needle crystal, soluble in hot water, easy vaporized, weak monobasic acid, Lewis acid, react with alcohol form borate ester, strong acid in diol, thermal dissociates to HBO2, complete fusion gives glass form, antibacterial additive
- planar unit, layers held by van der Waal forces (slippery)
Borate
- Boric acid + metal oxide
- Borax is borate species
- Uses: coloured glass, Pyrex glass
Boron Halide
-Prep: direct (BF₃ - heat with NH₄BF₄ & H₂SO₄)
- covalent, eassy vaporized, strong Lewis acid
Boron Nitride
- Prep.: Heat B₂O₃ in ammonia
- planar layer, slippery = lubricant, elec. insulator, refractory solid
Boranzine
- Similar structure to benzene but no delocalised e⁻
- Diborane + ammonia

Aluminium
- Prep.: Bayer Process (3 steps) them Hall-Heroult Process
- Direct with O, N, S & halides, react with HCl & H₂SO₄ but not HNO₃, react with base for aluminate ion
- Uses: powder catalyst, transports, alloy, constructions, electricals
Oxide
- alpha & gamma
- Prep.: Bayer Process, heating Al(OH)₃
- App.:
alpha - refractory, acid & hydration resistant, catalyst in dehydration.
gamma - catalyst, column chromatography, support for transition metal.
gemstones.
Hydrate
-  2 forms: alpha & gamma
Hydroxide
- Naturally Gibbsite
- Prep.: add ammonium hydroxide to Al3+ sol., acidification of aluminate
- white solid, amphoteric
- App.: mordant, coagulating agent
Halide
- AlF₃ monomeric, ionic solid, soluble, form salt with alkali metal, not Lewis acid
- AlCl₃ (dimeric - Al₂Cl₆), prep by pass dry HCl over hot Al or react between Al & HCl or heat Al₂O₃, lab prep using hot column reactor
- white solid, covalent
Alum
- Double sulphate of monovalent & trivalent metal ions with water
- Potash alum: colourless hexagonal crystal, soluble, hydrolyze in water
- Uses: mordant, tanning leather & sizing paper, stop bleeding