CHEMISTRY 5MOK 2020 by YASMIN BINTI NOORUL AMIN Moe

CHEMISTRY 5MOK 2020 by YASMIN BINTI NOORUL AMIN Moe https://padlet.com/g62372673/o7g41t225ewaa7en en-us 2020-11-02 07:53:46 UTC 2026-01-18 16:21:51 UTC hello@padlet.com TIMOTHY https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101066816 Duralumin - 95% Al
- 5% Cu, Mg, Mn
Uses

making the bodies of aircrafts and bullet trains
making racing bikes, fan blades, light electrical cables

Properties

Light and strong

Pewter - Sn (main)
- Cu
Uses

making mugs, candlesticks, decorative ornaments

Properties

Low melting point and boiling point
strong

]]> 2021-01-19 13:18:15 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101066816 Felix https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101076691 Dangers of synthetic polymers

Synthetic polymers are non- biodegradable. They will pollute our land, water and air.

Land
Non-biodegradable synthetic polymers wastes will block or clog the drainage system, thereby causing flash flood.

Water
The waste pollutes lakes and rivers with chemicals, causing the water not suitable for aquatic organisms to live in.

Air
The open burning of synthetic polymers gives out harmful , pungent acidic and poisonous gases that pollute the air . It causes green house effect and acid rain problems.]]> 2021-01-19 13:20:42 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101076691 Ahmad https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101092354
Preservatives
Provide acidic condition that stops the growth of microorganism
Example :
- vinegar -pickles

Function:
- prevent food from spoiling
-prevent or slow down the growth of microorganism
Example:
Sodium nitrate- sausage, burger
Sulphur dioxide - fruit juice, jam, soft drink
Sodium benzoate-chilli and oyster sauce, tomato ketchup, fruit juice
Salt - salted fish

]]> 2021-01-19 13:24:44 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101092354 Caleb https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101095211 Detergent and Additives
Detergent
- Prepared by sulphonation and neutralisation
- dissolves in water to form detergent and sodium ions
- detergent ions have hydrophilic head and hydrophobic tail
-Acts as a cleansing agent to lift greasy dirt from the surface of a cloth.

Additives
- Used to increase the cleansing power of detergent

Examples
1. Builders such as sodium tripolyphosphate
- used to soften hard water and removes calcium and magnesium ions

2.whitening/bleaching agents such as sodium perborate
- Removes coloured stains in the process and colour will disappear.

3. biological enzyme such as amylase, lipase, and protease
- breaks down fat and protein molecule in food stains so it can be removed during washing and rinsing process

4. brighteners
- makes fabrics appear brighter and whiter because it absorbs UV light and reradiates as blue light that covers the yellowing on cloth

5. drying agents such as anhydrous sodium sulphate and sodium silicate
- used to ensure detergent powders are always dry

6. stabilisers
- prevent the formation of excess foam

7. perfumes
- to make clothes smell fresh and clean.]]> 2021-01-19 13:25:30 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101095211 Arrvind https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101099658 natural rubber
the monomer = isoprene
IUPAC nomenoclature of isoprene = 2-methylbut-1,3-diene
the polymer= polyisoprene
molecular formula of isoprene =C5H8
molecular formula of natural rubber=(C5H8)n, n=10000

properties of natural rubber

Elasticity -
1) When natural rubber is stretched it straightens out easily and then returned to its original shape when the strain is removed.
2) This property enables rubber to be made into:
-glove
-shoe soles
-rubber band
-rubber tubing

oxidation -
1) Natural rubber is easily oxidised by O2 and ozone ( O3 )
2) Long polymer chains of rubber will become shorter chains after oxidation
3) This is due to the presence of double bonds that can be broken easily by O2 and ozone ( O3 )
4) Can be prevented by adding antioxidants ( like another carbon , special additives )

Effect of heat -
1) At low temp, natural rubber is HARD and BRITTLE
2) At high temp ,natural rubber is SOFT and STICKY
3) Natural rubber is not heat resistant
4) Makes it unsuitable to produce vehicle tyres

Effect of solvent -
1) Rubber is water repellent
2) Insoluble in water
3) soluble in organic solvent like benzene, petrol, lubricating oil, acids and alkalis.

]]> 2021-01-19 13:26:37 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101099658 Bronze vs Brass m3504084 https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101100072 Bronze

The composition of Bronze is Cu (main) and Sn (others)
Bronze is hard and strong.
Bronze is used to make kitchenware and ship’s propellers.
It is also used to make decorative ornaments, statues and art crafts.

Brass

The composition of Brass is also Cu (main) and Zn (others)
Brass is hard and shiny.
Brass is used to making electrical connectors and musical instruments. It is also used to make kitchenware and decorative ornaments.

]]> 2021-01-19 13:26:44 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101100072 Rashidul https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101101832 Psychotherapeutic drugs
(heal mind related disease)

1) Stimulant
- maintain alertness
- to counter fatigue and elevate mood
- example: caffeine (coffee), amphetamine

2) anti-depressant (depress CNS)
- to reduce depression
- relieve anxiety and tension
- make one calm and sleepy
- example: tranquilisers and barbiturates

3) anti-psychotic
- treat mental illness such as schizophrenia
- examples: Li2(CO3), chlorpromazine, haloperidol
- mental patients have extreme mood swings from highly spirited to deep depression.
- only suppress the effect of the symptoms

]]> 2021-01-19 13:27:08 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101101832 Yim https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101109730 PVC : Polyvinyl Chloride
(C2H3Cl)n
I. Monomer : Chloroethene, C2H3Cl
II. Uses : pipes, raincoat
III. Chemical Equation : n C2H3Cl > (C2H3Cl)n

Polystyrene
I. Monomer : Styrene, C6H5C2H3
II. Uses : To make packaging materials
III. Chemical Equation :
n C6H5C2H3 > (C6H5C2H3)n]]> 2021-01-19 13:29:02 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101109730 Imran ( Ester ) https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101112287 - carboxylic acid react with alcohol forms aster through esterification
- chemical formula of ester is CnHnCOOCnHn
- functional group of ester is carboxylate
- have sweet/pleasant smell
- insoluble in water
- lower in density than water
- oilly texture
- example of products ;
i) perfumes
ii) artificial flavour in food and drinks
iii) soap
- catalysts of ester are concentrated H2SO4 & K2Cr2O7, H+
- colour of K2Cr2O7 changes from orange -> green]]> 2021-01-19 13:29:41 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101112287 Allex m4249077 https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101112870 Food additives:(FLAVORING AGENT)
-To enhance the natural flavour of food.
-Produce artificial flavour(ester).
-Used as food sweetener.
Example of Food additives:
Monosodium glumate(MSG) A.K.A Ajinomoto,esters like ethyl butanoate(smell and taste like pineapple),aspartame,saccharin and stevia(a calorie-free substitude of sugar).
Example of foods that uses flavoring agent:
Soup(msg),fried rice(msg),coke(stevia),ice-cream(esters) and etc.

]]> 2021-01-19 13:29:50 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101112870 https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101116187 Liong
Antibiotics
-chemical that destroy the growth of infectious microorganism.
-used to treat disease caused by various bacteria.
-not effective against disease caused by viral infectious such as influenza,measles or small pox.
-example of antibiotic are penicillin and streptomycin.
-both penicillin and streptomycin are broken down by the acid in the stomach.
-usually given by injection and not taken orally.
-patients take all course of antibiotic to make sure that all the bacteria are killed.Otherwise,will ill again and the bacteria will more resistant to the antibiotic.
-side effect of antibiotic are headache,allergic reaction and diarrhoea

]]> 2021-01-19 13:30:42 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101116187 Azfar https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101123858 ELECTROPLATING IRON SPOON AND COPPER PLATE
1. Materials : Copper2 nitrate solution,copper plate,iron spoon,sand paper.
2. Apparatus : 250cm3 beaker,battery,connecting wires with crocodile clip.
3. Procedure :
- Pour 150cm3 of copper 2 nitrate solution into a 250cm3 beaker.
- Clean the iron spoon with sand paper to remove any impurities.
- Connect the iron spoon to negative terminal (cathode) of the battery.
- Connect the copper plate to the positive terminal (anode) of the battery/
- Dip both iron spoon and and copper plate into the copper2 nitrate solution.
- Complete and close the circuit and record the observation in a data table after 30 minutes.
4. Observations :
Anode- Becomes thinner
Cathode-Becomes thicker/Brown solid is deposited
5. Half equation :
Anode : Cu > Cu2+ + 2e
Cathode : Cu2+ + 2e > Cu
6. Labelled Diagram:
CORRECTION
* Copper2 nitrate
* Iron spoon]]> 2021-01-19 13:32:31 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101123858 Pavitheran https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101124984 REACTION OF ALKENE
Example: Pentene (C5H10)
1) Hydrogenetion (+H2){Ni/Pt,200°C}
Chemical equation
C5H10 +H2 --> C6H12
Pentene Pentane
2)Chlorination(+Cl2)
Chemical equation
C5H10 + Cl2 -->C5H10CL2
Pentene Dichloropentane
3)Bromination (+Br2)
Chemical equation
C5H10 + Br2 -->C5H10Br2
Pentene Dibromopentane
4)Hydration (+H20){H3PO4,300°C}
Chemical equation
C5H10 + H2O -->C5H11OH
Pentene Pentanol
5)Oxidation(+2[O]){KMnO4,H+}
Chemical equation
C5H10 + 2[O] -->C5H10(OH)2
Pentene Pentan-1,2-di-ol
6)Reaction of hydrogen halides (+HBr)
Chemical equation
C5H10 + HBr --> C5H11Br
Pentene Bromopentane

]]> 2021-01-19 13:32:47 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101124984 JOSHUA joshuasubramaniam582 https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101128773 Stabilisers and Thickening Agents
-Stabilisers and thickening agents are used to improve the texture of food.
-Examples of stabilisers are gelatin,acacia gum,lecithin and pectin.So stabilisers are added to ice cream to make them feel creamy and nice.
-Thickening agents are added to food to thicken the liquid and to prevent the food from liquefying.They absorb water and thicken the liquid in food to produce a jelly like structure.
-Examples of stabilisers are gelatin and pectin.They are added to help jam and jellies to set.]]> 2021-01-19 13:33:37 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101128773 Ariff https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101129574 Composite material
-Materials made from two or more constituent materials with significantly different physical or chemical properties. The two materials combined together to give the composite desirable properties,

-Consist of a mixture of two or more materials such as metals, alloys, ceramics, carbon and polymer.

-Generally, composite materials have better properties of the original material.

Types of composite materials and its uses.
-Reinforced concrete
○ Compositions: mixture of cement, gravel, sand water, iron/steel to produce nets, rods or bars.

○ Properties: strong, high tensile
○ Uses: construction material for highways, buildings and bridges.

-Superconductor
○ Compositions: Mixture of various components such as niobium and germanium.

○ Properties: No electrical resistance(zero resistance). Only can function under an extremely low temperature.
○ Uses: Materials for transportation, telecommunication and astronomy, industry and medical.

-Fibre glass
○ Compositions: Mixture of silica, sodium carbonate and calcium carbonate.

○ Properties: Good insulator of heat and electricity.
○ Uses: Protective apparel materials for astronauts and fire-fighters.

-Fibre optic
○ Compositions: Mixture of glass, copper and aluminium.

○ Properties: Enables information to be transmitted in light form at high speeds.
○ Uses: Electrical cables in communication industry and cables used in medical field to observe internal organs without performing surgery.

-Photochromic glass
○ Compositions: Molten silica mixed with a little argentum chloride.

○ Properties: Dark-coloured when exposed to bright light and bright when in the dark.
○ Uses: Optical lenses and glass windows for vehicles.

-Ceramic glass
○ Compositions: Exposing glass that contains certain amount of metals to ultraviolet rays and heating it at a high temperature.

○ Uses: Cooking materials and rocket heads.

-Plastic strengthened with glass fibres
○ Compositions: Mixture of plastic and glass fibres

○ Properties: Very strong, light, easily formed and can withstand corrosion.
○ Uses: Make helmets, the body of cars and aeroplanes, rods and other parts of aeroplanes]]> 2021-01-19 13:33:48 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101129574 Kiruba https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101136370 ALCOHOL

FG: hydroxyl,OH
GF: CnH2n

Physical Prop
- sharp smell
- Low BP
- colourless

Chemical prop
- oxidation
Alcohol + 2[0] = carboxylic acid
- dehydration
Ethanol ———> ethene gas + water
- combustion
Alcohol + oxygen gas = CO2 + H2O
- fermentation of glucose

]]> 2021-01-19 13:35:22 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101136370 Analgesic https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101143843 Lmf
Aspirin
-relief pain and has anti-inflammatory action - reduce fever - relieve headache, muscle and joint aches
-Treat arthritis - inflammation of the joint
-Anticoagulant effect on blood, reduce the risk of heart attack and strokes
Side effect
Can cause bleeding in stomach as aspirin is acidic
Can cause allergic reaction, skin rashes, asthmatic attacks

Paracetamol
- similar to aspirin in effects but it does not reduce inflammation
-reduce and relieve flu symptoms such as fever, bone aches, runny nose

Codeine
-use to relieve minor to mederate pain
-more powerful than aspirin and paracetamol, less power than morphine(narcotic drug)
Also use in cough mixture to surpress cough
Side effect
Addiction]]> 2021-01-19 13:37:06 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101143843 Kautaam https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101152285 Food Colourings

Food Colour are substances added to food (include solid food and drinks) to give it a new colour. It must be noted that food dyes can be synthesised or can also be obtained naturally.

The natural colours of food maybe lost during the process.You may not want to eat food that are not the colour you expect.Colourings replace these lost colours,they are also added to make the food to make it look more attractive to the consumers

]]> 2021-01-19 13:39:05 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101152285 Metal Purification https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101160834 SARENDREN

1) Impure metal that contain impurities can be purified through electrolysis
2) Impure metal is anode and pure metal is cathode
3) Solution that contains ion of the metal to purify is electrolyte
4) After electrolysis the mass of pure metal will increases and the impure metal decreases

]]> 2021-01-19 13:40:55 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101160834 Adzrien [CONTACT PROCESS] https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101161629 Process in the manufacture of Sulphuric Acid.

Materials: Sulphur (from burning petroleum), Oxygen, Water.
Catalyst: Vanadium (V) oxide, V2O5.
Temperature: 450° - 550°C.
Pressure: 1 atm.

Equations:-
• S + O2 > SO2(g)
• 2SO2 + O2 > 2SO3
• SO3 + H2SO4(conc) > H2S2O7(oleum)
• H2S2O7 + H2O > 2H2SO4

...

*PRECAUTIONS*
Sulphur trioxide is not dissolved directly in water because:
(i) SO3 is not so soluble in water.
(ii) SO3 reacts vigorously in water, producing a large amount of heat which will vaporise sulphuric acid to form acid mist.
(iii) The mist is corrosive,pollutes the air and difficult to condense.

...

*POLLUTION ISSUES*
a. Main source - burning of petroleum.
b. SO2 - acidic and corrosive
c. Can affect the respiratory system and causes pollution probs.
d. Can also cause acid rain.

...

How gases from Contact process can cause environmental pollution:-
1. The gases will react with the water in the cloud.
2. To form acid rain.
3. Metal structures such as bridges and paint of buildings will be corrodes.
4. Causes acidity of soil to increase - kill plants.
5. Causes acidity of water sources to increase - kill aquatic life.]]> 2021-01-19 13:41:07 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101161629 Aidil https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101167953 Glass
*FUSED GLASS*
[ Properties ]
• Highly resistant to chemical reaction
• Transparent to UV and IR light
• Difficult to shape
• Does not crack when temperature rises
[ Chemical Composition ]
• SiO2 ( 90% )
• B2O3 ( 1% )
[ Example ]
• Telescope mirrors
• Lenses
• Optical fibres
*BOROSILICATE GLASS*
[ Properties ]
• High softening points ( 800°C )
• Heat resistant
• Does not crack easily with sudden temperature change
• Transparent to UV light
• Does not break easily
[ Chemical Composition ]
• SiO2 ( 80% )
• B2O3 ( 15% )
• NA2O ( 3% )
• Al2O3 ( 1% )
[ Example ]
• Lab apparatus
• Cooking utensils
• Electrical tubes

]]> 2021-01-19 13:42:31 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101167953 Anas https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101171189 𝗣𝗵𝗼𝘁𝗼𝗰𝗵𝗿𝗼𝗺𝗶𝗰 𝗚𝗹𝗮𝘀𝘀

— 𝗦𝗲𝗻𝘀𝗶𝘁𝗶𝘃𝗲 𝘁𝗼 𝗹𝗶𝗴𝗵𝘁 𝗶𝗻𝘁𝗲𝗻𝘀𝗶𝘁𝘆 .
— 𝗗𝗮𝗿𝗸𝗲𝗻𝘀 𝘄𝗵𝗲𝗻 𝗲𝘅𝗽𝗼𝘀𝗲𝗱 𝘁𝗼 𝘀𝘂𝗻𝗹𝗶𝗴𝗵𝘁 but 𝗯𝗲𝗰𝗼𝗺𝗲𝘀 𝗰𝗹𝗲𝗮𝗿 𝘄𝗵𝗲𝗻 𝗹𝗶𝗴𝗵𝘁 𝗶𝗻𝘁𝗲𝗻𝘀𝗶𝘁𝘆 𝗱𝗲𝗰𝗿𝗲𝗮𝘀𝗲𝘀 .

Produced when 𝘀𝗶𝗹𝘃𝗲𝗿 𝗰𝗵𝗹𝗼𝗿𝗶𝗱𝗲 , 𝗔𝗴𝗖𝗹 / 𝘀𝗶𝗹𝘃𝗲𝗿 𝗯𝗿𝗼𝗺𝗶𝗱𝗲 , 𝗔𝗴𝗕𝗿 is added to normal glass .

When exposed to 𝘂𝗹𝘁𝗿𝗮𝘃𝗶𝗼𝗹𝗲𝘁 𝗹𝗶𝗴𝗵𝘁 , 𝗔𝗴𝗖𝗹 / 𝗔𝗴𝗕𝗿 𝗱𝗲𝗰𝗼𝗺𝗽𝗼𝘀𝗲𝘀 𝘁𝗼 𝗳𝗼𝗿𝗺 𝘀𝗶𝗹𝘃𝗲𝗿 and 𝗵𝗮𝗹𝗼𝗴𝗲𝗻𝘀 𝗮𝘁𝗼𝗺𝘀 . The fine silver deposited in glass is 𝗯𝗹𝗮𝗰𝗸 and the glass is 𝗱𝗮𝗿𝗸𝗲𝗻𝗲𝗱 .

𝗘𝘅 : ( 𝗨𝗩 )
𝗔𝗴𝗕𝗿 ————> 1/2 𝗕𝗿2

When the ultraviolet ray intensity 𝗱𝗲𝗰𝗿𝗲𝗮𝘀𝗲𝘀 , silver atoms and bromine gas recombine to form 𝘀𝗶𝗹𝘃𝗲𝗿 𝗯𝗿𝗼𝗺𝗶𝗱𝗲 . ]]> 2021-01-19 13:43:14 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101171189 Baret (vulcanized rubber vc unvulcanized rubber) https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101174384 1.Vulcanized rubber is rubber that has undergone the process of vulcanization. Unvulcanized rubber is rubber that has not undergone the process of vulcanization.
2.Vulcanized rubber has an intermolecular system with highly cross-linked polymer chains.

Unvulcanized rubber only has polymer chains, doesn’t have cross-links or intermolecular networks.
3.Vulcanized is the process carried out by heating the rubber, mixed with a vulcanizing agent in a mold under pressure.
4.Vulcanized rubber forcibly retracts to its original shape without imposing deformations once the mechanical stress is released.Unvulcanized rubber imposes deformation when undergoing large mechanical stresses.
5.Vulcanized rubber: Chemical composition is changed by the addition of curing agents.
Unvulcanized rubber:There is no such change in chemical composition.
6.Vulcanisation is the process of hardening rubber by heating it with monosulphur monochloride or disulphur monochloride.

]]> 2021-01-19 13:43:58 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101174384 https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101176483 Polyethylene is of low strength, hardness and rigidity, but has a high ductility and impact strength as well as low friction.Melting point: 115–135 °C Low Density Polyethylene (LDPE),uses are sandwich bags, cling wrap, car covers, squeeze bottles, liners for tanks and ponds, moisture barriers in construction.High Density Polyethylene (HDPE),uses are freezer bags, water pipes, wire and cable insulation, extrusion coating

]]> 2021-01-19 13:44:28 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101176483 Extraction of Aluminium from Aluminium Oxide m3502255 https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101177231 Bauxite contains aluminium oxide (Al₂O₃)

Cryolite (Na₃AlF₆) is mixed with aluminium oxide (Al₂O₃) to lower its melting point from 2000°C to 950°C

Molten aluminium oxide is electrolysed using graphite as electrode.

Half equation:
At cathode:
Al³⁺ + 3e > Al
At anode:
2O^2- > O₂ + 4e

Overall ionic equation:
4Al³⁺ + 6O^2- > 4Al + 3O₂

The carbon anode must be replaced time to time because the oxygen released will oxidise the carbon anode to form carbon dioxide (CO₂)

Diagram:

]]> 2021-01-19 13:44:39 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101177231 NG Chee Yung https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101188136 HABER PROCESS
-Process to produce ammonia using hydrogen gas and nitrogen gas
-Nitrogen gas is obtained through fractional distillation of liquid air
-Hydrogen gas is obtained through...
*the reaction between steam and heated coke
*the reaction between steam and natural gas
-Process:
~A mixture of ratio 1 volumes of nitrogen gas and 3 volumes of pure dry H2 is compressed at 200-500 atm
~the gas mixture is passed through iron powder as a catalyst at 450°-550°C
~the product is cooled then liquefied.
-Unreacted nitrogen and hydrogen gas is pumped back to the catalytic column to be reacted again
-equation:
N2 + 3H2 = 2NH3

]]> 2021-01-19 13:47:07 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101188136 Adam -lead glass , Soda lime glass https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101189764 Lead glass

-low softening point (600°c)
- high density
-high refractive index
-reflects light rays and appears sparkling

- SiO²(55%)
-PbO (30%)
-K2O (10%)
Na²O (3%)
Al²O² (2%)

Uses

-deco items , crystal glassware , lens , prism and chandeliers

Soda lime glass

-break easily
-cracks easilg when jn sudden temperature changes

SiO² (70%)
Na²O (15%)
CaO (10%)

Uses
-bottle
-window
- light bulbs
-mirrors
-flat glasses]]> 2021-01-19 13:47:27 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101189764 Adib - Traditional Medicine https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101189899 Garlic ( corm )
- to prevent flu/asthma attacks
- reduce high blood pressure

Ginger ( rhizome )
- treat stomach pain due to wind
- supply heat to keep the body warm
- prevent flu attack

Aloe Vera ( leaves )
- treat itchy skin
- treat burns (scalding) on skin

Lime ( fruits )
- treat boils or abscesses on skin
- prevent flu attack
- treat skin diseases

Quinine ( bark of Cinchoma tree )
- treat malaria
- prevent muscle cramps

Ginseng ( roots )
- as a tonic to improve the overall health of human beings
- increase energy, endurance
- reduce fatigue

Lemon grass ( stem/leaves )
- has antibacterial and antifungal properties
-treating coughs

Tongkat Ali ( roots )
- tonic for after birth and general health

Side effect of traditional medicine :
- high dose of quinine can cause liver damage

]]> 2021-01-19 13:47:29 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101189899 https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101190484

Polypropylene is a tough, rigid and crystalline thermoplastic produced from propene (or propylene) monomer. It is a linear hydrocarbon resin. The chemical formula of polypropylene is (C₃H₆)_n. PP is among the cheapest plastics available today.

PP belongs to polyolefin family of polymers and is one of the top three widely used polymers today. Polypropylene has applications both as a plastic and a fiber in:

Automotive Industry
Industrial Applications
Consumer Goods, and
Furniture Market

Melting Point of Polypropylene - The melting point of polypropylene occurs at a range.

Homopolymer: 160 - 165°C
Copolymer: 135 - 159°C

Density of Polypropylene - PP is one of the lightest polymers among all commodity plastics. This feature makes it a suitable option for lightweight\weight saving applications.
- Homopolymer: 0.904 – 0.908 g/cm³
- Random Copolymer: 0.904 – 0.908 g/cm³
- Impact Copolymer: 0.898 – 0.900 g/cm³

Polypropylene Chemical Resistance
- Excellent resistance to diluted and concentrated acids, alcohols and bases
- Good resistance to aldehydes, esters, aliphatic hydrocarbons, ketones
- Limited resistance to aromatic and halogenated hydrocarbons and oxidizing agents

Flammability: Polypropylene is a highly flammable material

PP retains mechanical & electrical properties at elevated temperatures, in humid conditions and when submersed in water. It is a water-repellent plastic

PP has good resistance to environmental stress cracking

It is sensitive to microbial attacks, such as bacteria and mold

It exhibits good resistance to steam sterilization

]]> 2021-01-19 13:47:36 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101190484 Antioxidants m3835682 https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101198971 What are antioxidants?
Antioxidants are substances that protect our cells against free radicals. Free radicals are unstable atoms that can damage cells, causing illness and aging. Free radicals come in many forms, such as fried foods, alcohol, tobacco smoke, air pollutants and many more.

Why are they important?
A diet in high antioxidants may reduce the risk of many diseases such as heart disease and cancer. Antioxidants scavenge free radicals from the body cells and prevent or reduce the damage caused by oxidation.

Sources of antioxidants
The sources of antioxidants can be natural or artificial. Certain plant-based foods are thought to be rich in antioxidants. Vegetables such as broccoli, spinach and carrots are rich in natural antioxidants. Besides that there are antioxidant food additives such as ascorbic acid and citric acid.

Example of foods that use antioxidant food additives
Cake, biscuit, margarine, fruit juice

Why are antioxidants added to the foods above?
Antioxidants are used to prolong the oxidation process of processed foods. This increases the shelf life of that material. For example, in fats and oils, antioxidants slow the rate of oxidising reactions. Fats and oils most commonly spoil as oxidation of the lipids cause production of compounds that lead to bad odours and differed taste in the product.

]]> 2021-01-19 13:49:30 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101198971 Seeralan https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101201691 Title : Carbon steel vs Stainless steel

CARBON STEEL
Made up of : 99 % Fe
1% C
Properties:
1. Hard
2. Strong

Functions :
1. Frameworks of building and bridges
2. Making tools , framework of heavy machinery , body of vehicles

STAINLESS STEEL
Made up of : 75 % Fe
20 % Cr , Ni
Properties:
1. Hard
2. Can resist corrosion

Functions :
1. Making cutlery and kitchenware
2. Making machine parts and surgical equipments

]]> 2021-01-19 13:50:04 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101201691 Viki https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101214562 HOMOLOGOUS SERIES:- ALKANE
FUNCTIONAL GROUP:- SINGLE BOND
GENERAL FORMULA:- CnH2n+2

3 types of reactions:-

1) COMPLETE COMBUSTION [+O2]

example:- Hexane

C6H14 + 19/2 O2 -------> 6CO2+7H20

2) CLORINATION [+Cl2]

Condition:-25°C and Urlight

example:- Hexane

C6H14 + Cl2 -----------> C6H14Cl2

3) CRACKING

Condition:- i.Temperature-600°C
ii. Catalyst- Al3O3

example:- Hexane

C6H14 ---------> C6H12 +H2

DIFFERENCE BETWEEN ALKANE AND ALKENE

GENERAL FORMULA:- i) ALKANE- CnH2n+2
ii) ALKENE - CnH2n

FUNCTIONAL GROUP:- i) ALKANE - SINGLE BOND
ii) ALKENE- DOUBLE BOND BETWEEN 2 CARBON ATOMS

TYPE OF HYDROCARBON:- i) ALKANE- SATURATED HYDROCARBON

ii) ALKENE- UNSATURATED HYDROCARBON

ALKANE HAVE 3 TYPES REACTIONS

1) COMPLETE COMBUSTION
2) CLORINATION
3) CRACKING

ALKENE HAVE 7 TYPES OF REACTIONS

1) COMPLETE COMBUSTION
2) CLORINATION
3) HYDROGENATION
4) BROMINATION
5) HYDRATION
6) OXIDATION
7) POLYMERISATION

]]> 2021-01-19 13:52:45 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101214562 Chin https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101214890 Preparation of copper (II) sulphate salt
Apparatus: 250 cm3 beaker, filter funnel, filter paper, spatula, glass rod, evaporating dish, Bunsen burner, tripod stand, wire gauze, dessicator, measuring cylinder
Material: 1.0 mol dm-3 sulphuric acid solution, copper (II) oxide powder, distilled water
Procedure:
1. Measure and pour 50 cm3 1.0 mol dm-3 sulphuric acid solution into a 250 cm3 beaker.
2. Gently heat the sulphuric acid solution.
3. Using a spatula, add copper (II) oxide powder into the sulphuric acid solution.
4. Stir the solution.
5. Add the copper (II) oxide powder until it can no longer dissolve.
6. Filter the solution to remove the excess copper (II) oxide powder.
7. Pour the salt solution obtained into an evaporating dish.
8. Heat the solution until 1/3 is left.
9. Cool the saturated salt solution to be crystalised.
10. Wash and filter the salt solution.
11. Dry the salt crystals in a dessicator.
Chemical equation: CuO + H2SO4 --> CuSO4 + H2O]]> 2021-01-19 13:52:49 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101214890 Loganathan - carboxylic acid https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101238683 - Carboxylic acids are organic acids that have the general formula CnH2n+1COOH where n is 0,1,2,3
- Functional group of carboxylic acids is the carboxyl group,-COOH
- Name of the carboxylic acid will depend on the number of carbon atoms in its molecule
- Carboxyl group consists of a carbon atom which forms a double bond with oxygen atom and a single covalent bond with the hydroxyl (-OH) group
*preparation of carboxylic acid
- Ethanol Ethanoic acid
- Propanol OXIDATION Propanoic acid
- Butanol Butanoic acid

]]> 2021-01-19 13:57:45 UTC https://padlet.com/g62372673/o7g41t225ewaa7en/wish/1101238683