Polymers

Polymers
1. Polymer – many small units (monomers) joining together to formed large molecule.
2. Polymer can be classified into two groups:

• synthetic polymers / man-made polymers (polythene; PVC – polyvinyl chloride; artificial silk; and polypropene)
• natural polymers (natural rubber; starch; cellulose; and proteins)

3. Natural polymer: Carbohydrates (polysaccharides) (starch, glycogen and cellulose)

• General formula: C_x(H₂O)_y with the ratio of H:O = 2:1
• Carbohydrates have cyclic structure.
• Monomer: glucose (C₆H₁₂H₆)
• Reaction to form polymer: condensation reaction (- H₂O)

4. Natural polymer: Protein (polypeptide)

• Protein consists of carbon, hydrogen, oxygen and nitrogen (some have sulphur, phosphorus and other elements)
• Monomer: amino acids
• Amino acids have two functional group which are carboxyl group (-COOH) and amino group (-NH₂)
• Reaction to form polymer: condensation reaction (- H₂O)

5. Natural polymer: Natural rubber

• Extracted from the latex of rubber tree (Hevea brasiliensis) which the tree originates from Brazil.
• A molecule of rubber contains 5000 isoprene units.
• Monomer: isoprene, C₃H₈ or 2-methylbuta-1,3-diene.
• Reaction to form polymer: additional polymerisation (one of the double bond in isoprene becomes single bond)

6. Structure of rubber molecule

• Latex is colloid (35% rubber particles and 65% water).
• Rubber particle contains rubber molecules which are wrapped by a layer of negatively-charged protein membrane. Same charge of rubber molecules repels each other. This prevent rubber from coagulate.

7. Coagulation process of latex
The process for the coagulation of latex is summarised as:

1. Acid (H⁺) can neutralise the negatively-charged protein membrane. Example of acid: formic acid, methanoic acid, suphuric acid and hydrochloric acid.
2. The rubber molecules will collide after the protein membrane is broken.
3. Rubber molecules (polymers) are set free
4. Rubber molecules combine with one another (coagulation).

8. Natural coagulation process of latex
For the natural coagulation of latex:

1. Latex is exposed to air without adding acid (duration – overnight).
2. Coagulation process occurs in slower pace due to the bacteria (microorganism) action which produce acid)

9. Prevent coagulation process of latex
The following are latex coagulation prevention method:

1. Alkaline / Basic solution is added to the latex. Example: ammonia (NH₃).
2. Positively-charged hydrogen ion / H⁺ produced by bacteria can be neutralised by negatively-charged hydroxide ion / OH^- from ammonia solution.

10. Properties of natural rubber

• elastic
• cannot withstand heat (become sticky and soft – above 50°C; decompose – above 200°C; hard and brittle – cooled)
• easily oxidised (present of C=C)
• insoluble in water (due to the long hydrocarbon chains)
• soluble in organic solvent (propanone, benzene, petrol etc.)

11. Vulcanisation of rubber
Vulcanisation – process of hardening rubber and increases rubber elasticity by heating it with sulphur or sulphur compounds.
Methods:

• heating natural rubber with sulphur at 140°C using zinc oxide as catalyst or
• dipping natural rubber in a solution of disulphur dichloride (S₂Cl₂) in methylbenzene.

12. Properties of vulcanisation of rubber

• The sulphur atoms are added to double bonds in the natural rubber molecules to form disulphide linkages (-C-S-S-C-) / sulphur cross-links between the long polymer chains. Therefore, vulcanised rubber is more elastics and stronger.
• This increases the molecular size and the intermolecular forces of attraction between rubber molecules. Therefore, vulcanised rubber is more resistant to heat (does not become soft and sticky when hot).
• This also reduces the number of carbon-carbon double bonds in rubber molecules. Therefore, vulcanised rubber is more resistant to oxygen, ozone, sunlight and other chemicals.

13. Comparison between the properties of vulcanised rubber and unvulcanised rubber

Properties	Vulcanised rubber	Unvulcanised rubber
Double bonds	Decreases (formation of sulphur cross-links)	More number of double bonds
Melting point	High (presence of sulphur)	Low
Elasticity	More elastic (sulphur cross-links prevents the polymer chain or rubber from slipping past.	Less elastics
Strength and hardness	Strong and hard (depends on degree of vulcanisation)	Weak and soft (polymer chain of rubber will break when rubber is over stretched.
Resistant to heat	Resistant to heat	Poor resistant to heat
Oxidation	Resistant to oxidation (reduction of number of double bonds per rubber molecule)	Easily oxidised by oxygen, UV light (presence of many double bonds per rubber molecules)

14. R & D of rubber

• RRIM – Rubber Research Institute of Malaysia
• MRB – Malaysian Rubber Board
• Rubber Technology Centre
• Various local higher institutions of learning

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Non-Hydrocarbon – Fats

Non-Hydrocarbon – Fats
1. Fatrs are non-hydrocarbons which contain carbon, hydrogen and oxygen atoms.
2. Fats (lipids / triglycerides) are belonging to the group in ester.
3. Natural esters are formed from glycerol and fatty acids.

Name of fat	Molecular formula of ester	Types of fatty acids
Lauric acid*	CH3(CH2)10COOH	Saturated
Palmitic acid*	CH3(CH2)14COOH	Saturated
Stearic acid*	CH3(CH2)16COOH	Saturated
Oleic oxide **	CH3(CH2)7CH=CH(CH2)7COOH	Unsaturated
Linoleic acid***	CH3(CH2)4CH=CHCH2CH=CH(CH2)7COOH	Unsaturated
Linolenic acid***	CH3CH2CH=CHCH2CH=CHCH2CH=CH(CH2)7COOH	Unsaturated

* Saturated: C-C single bonds
** Unsaturated (monounsaturated): C=C double bonds
*** Unsaturated (polyunsaturated): C=C double bonds
4. Animal fats have higher percentage of saturated fatty acids than unsaturated fatty acids.
5. Plant oils have higher percentage of unsaturated fatty acids than saturated fatty acids.
6. Physical properties of fats

	Saturated	Unsaturated
Types of fatty acids	C-C single bonds	C=C double bonds
Bonding	single	double
Melting point	higher	lower
Sources	animals	plants
Cholesterol	high	low
State at room temperature	solid	liquid

Fats (animal) in general are solids at room temperature and acted as:

• thermal insulator
• protective cushion to protect the vital organ
• provide energy and stored in body
• carry Vitamin A, D, E, K (insoluble in water)
• Example: butter, fish oil (liquid in room temperature)
• Fats (plant) are called oils. Oils are liquids at room temperature.
• Example: olive oil, peanut oil, palm oil and bran oil

7. Chemical properties of fats

• Unsaturated fats can be converted into saturated fats by hydrogenation (additional reaction) in 200°C and 4 atm in the presence of nickel catalyst.
• Example: production of margarine from sunflower oil of palm oil.

8. Effect of fats
Fatty food produce high energy but high consumption of fatty food will results:

• obesity
• raise the level of cholesterol
• deposition will cause block the flow of blood which lead to stroke and heart attack.

9. Palm oil

• It is extracted from fresh oil palm fruits.
• Palm oil – extracted from the pulp of the fruits.

Steps in extraction of palm oil:

1. sterilising (oil palm fruit)
2. stripping
3. digestion (crushing the husk and fruit and separate the oil by heating)
4. squeezed out the oil
5. extraction (separate the oil from water)
6. purification the oil (palm oil is treated with phosphoric acid and then steam is passed through to separate the acid)
7. vacuum

Palm kernel oil – extracted from the kernel or seed.
Steps in extraction of palm oil:

1. sterilising (oil palm fruit)
2. stripping
3. crushing the husk and fruit
4. extracting kernel oil
5. purification (purify the oil from kernel)

Goodness in palm oil:

• higher proportion of unsaturated fats.
• easy to digest and absorb.
• rich in vitamin A (carotenoid)
• rich in vitamin E (tocophenols and tocotrienols)
• resist oxidation in high temperature.

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Non-Hydrocarbon – Esters

Non-Hydrocarbon – Esters
1. General formula: C_nH_2n+1COOC_mH_2m+1
Where n = 0, 1, 2, 3 … and m = 1, 2, 3 … (n and m = number of carbon)
RCOOR‘ where R and R‘ represented the same or different alkyl groups.
2. Esters are non-hydrocarbons which contain carbon, hydrogen and oxygen atoms.
3. The functional group in ester is carboxylate group, – COO -.
C_nH_2n+1COOH + C_mH_2m+1OH –> C_nH_2n+1COOC_mH_2m+1 + H₂O

• First part: taken from the alcohol (alkyl group)
• Second part: taken from the carboxylic acid (-oic to -oate)

Name of ester	Molecular formula of ester	Prepared from
Ethyl methanoate	HCOOC2H5	Ethanol + Methanoic acid
Methyl ethanoate	CH3COOCH3	Methanol + Ethanoic acid
Propyl ethanoate	CH3COOC3H7	Propanol + Ethanoic acid
Ethyl propanoate	C2H5COOC2H5	Ethanol + Propanoic acid

4. Physical properties of ester

Name	Odour
3-metylbutyl acetate	Banana
Ethyl butanoate	Pineapple
Octyl ethanoate	Orange
Isoamyl isovalerate	Apple

• Simple esters are colourless liquid and are found in fruits and flowers.
• Esters have sweet pleasant smell.
• Esters are covalent compounds.
• Esters are insoluble in water but soluble in organic solvent.
• Esters are less dense than water.
• Esters are neutral and cannot conduct electricity.
• The higher and more complex esters have higher boiling points and less volatile.

Natural sources:

• Vegetable oils (palm oil) and liquids esters can be found in plants derived from glycerol and fatty acids.
• Fats are solid esters (milk fat) derived from glycerol and fatty acids.
• Waxes (beewax) are solid ester derived from long-chain fatty acids and long-chain alcohols.

5. Uses of Esters

• Preparation of cosmetics and perfumes (esters are volatile and have sweet smell).
• Synthetic esters used as food additives (artificial flavour).
• Natural esters serves as storage reserve of energy in living things.
• In plant, wax (esters) helps to prevent dehydration and attack of microorganisms.
• Esters used as solvents for glue and varnishes.
• Esters used to make plastics softer.
• Esters used to produce polyester (threads and synthetics fabrics)
• Esters used to produce soap and detergents.

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Non-Hydrocarbon – Carboxylic Acids

Non-Hydrocarbon – Carboxylic Acids
1. General formula: C_nH_2n+1COOH

• Where n = 0, 1, 2, 3 … (n = number of carbon)

2. Carboxylic acids are non-hydrocarbons which contain carbon, hydrogen and oxygen atoms.
3. The functional group in alcohols is carboxyl group, – COOH.

Name of carboxylic acids	Molecular formula of alcohol
Methanoic acid(Formic acid)	HCOOH
Ethanoic acid(Acetic acid)	CH3COOH
Propanoic acid	C2H5COOH
Butanoic acid	C3H7COH

4. Physical properties of carboxylic acid

Name	Molecularformula	Boiling point (°C)
Methanoic acid(Formic acid)	HCOOH	101
Ethanoic acid(Acetic acid)	CH3COOH	118
Propanoic acid	C2H5COOH	141
Butanoic acid	C3H7COH	164

• Solubility in water – generally in carboxylic acid (the less than four carbon atoms) are very soluble in water and ionise partially to form weak .
• Density of carboxylic acid – density of carboxylic acid increases due to the increases in the number of carbon atoms in a molecule.
• Boiling points – all carboxylic acid in general have relatively high boiling points than the corresponding alkanes. This is due to the presence of carboxyl group in carboxylic acid.
• Smell – carboxylic acid (< 10 carbon) are colourless and pungent smell. Carboxylic acid (>10 carbons) are wax-like solids.

5. Preparation of carboxylic acid

• Oxidation of an alcohol
  The oxidation of ethanol is used to prepare ethanoic acid.
  C₂H₅OH + 2[O] –> CH₃COOH + H₂O
  Carried out by refluxing* ethanol with an oxidising agent
  [acidified potassium dichromate(VI) solution – orange colour turns to green /
  acidified potassium manganate(VII) solution – purple colour turns to colourless]
  * reflux = upright Liebig condense to prevent the loss of a volatile liquid by vaporisation.

6. Chemical properties of carboxylic acid

• Acid properties
  Ethanoic acid is a weak monoprotic acid that ionises partially in water (produce a low concentration of hydrogen ions).
  CH₃COOH <–> CH₃COO^- + H⁺
  Ethanoic acid turns moist blue litmus paper red.
• Reaction with metals
  Ethanoic acid reacts with reactive metals (copper and metals below it in the reactivity series cannot react with ethanoic acid).
  (K, Na, Mg, Al, Zn, Fe, Sn, Pb, Cu, Hg, Au)
  2CH₃COOH + Zn –> Zn(CH₃COO)₂ + H₂
  In this reaction, a colourless solution (zinc ethanoate) is formed.
  2CH₃COOH + Mg –> Mg(CH₃COO)₂ + H₂
  In this reaction, a colourless solution (magnesium ethanoate) is formed.
• Reaction with bases
  acid neutralises alkalis (sodium hydroxide).
  CH₃COOH + NaOH –> CH₃COONa + H₂O
  In this reaction, a salt (sodium ethanoate) and water are formed.
• Reaction with carbonates
  Ethanoic acid reacts with metal carbonates (calcium carbonate, magnesium carbonate, zinc carbonate).
  2CH₃COOH + CaCO₃ –> Ca(CH₃COO)₂ + CO₂ + H₂O
  In this reaction, a salt (calcium ethanoate), carbon dioxide and water are formed.
• Reaction with alcohols (Esterification)
  Ethanoic acid reacts with alcohol (ethanol, propanol, butanol)
  CH₃CO-OH + H-OC₄H₉ –> CH₃COOC₄H₉ + H₂O (Concentrated H₂SO₄ is a catalyst)
  In this reaction, an ester (colourless sweet-smelling liquid) (butyl ethanoate) and water are formed.

7. Uses of Carboxylic Acid

• Carboxylic acid (methanoic acid and ethanoic acid) is used to coagulate latex.
• Vinegar (dilute 4% of ethanoic acid) is used as preservative and flavouring.
• Ethanoic acid is used to make polyvinvyl acetate which is used to make plastics and emulsion paints.
• Benzoic acid is used as food preservative.
• Butanoic acid is used to produce ester (artificial flavouring).

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Non-Hydrocarbon – Alcohol

Non-Hydrocarbon – Alcohol
1. General formula: C_nH_{2n + 1}OH

• Where n = 1, 2, 3 … (n = number of carbon)

2. Alcohols are non-hydrocarbons which contain carbon, hydrogen and oxygen atoms. 3. The functional group in alcohols is hydroxyl group, – OH.

Name of alcohol	Molecular formula of alcohol
Methanol	CH3OH
Ethanol	C2H5OH
Propanol / Propan-1-ol	C3H7OH
Butanol / Butan-1-ol	C4H9OH
Pentanol / Pentan-1-ol	C5H11OH
Hexanol / Hexan-1-ol	C6H13OH
Heptanol / Heptan-1-ol	C7H15OH
Octanol / Octan-1-ol	C8H17OH
Nonanol / Nonan-1-ol	C9H19OH
Decanol / Decan-1-ol	C10H21OH

4. Physical properties of alcohol

Name	Molecular formula	Melting point (°C)	Boiling point (°C)	Physical state at 25°C
Methanol	CH3OH	-97	65	Liquid
Ethanol	C2H3OH	-117	78	Liquid
Propanol	C3H5OH	-127	97	Liquid
Butanol	C4H7OH	-90	118	Liquid
Pentanol	C5H9OH	-79	138	Liquid

• Solubility in water – all members in alcohol are very soluble in water (miscible with water).
• Volatility – all alcohols are highly volatile.
• Colour and Smell – alcohols are colourless liquid and have sharp smell.
• Boiling and melting points – all alcohols in general have low boiling points (78°C).

5. Chemical properties of alcohol

• Combustion of alcohol Complete combustion of alcohol. C₂H₅OH + 3O₂ –> 2CO₂ + 3H₂O (Alcohol burns with clean blue flames. Alcohol burns plenty of oxygen to produce carbon dioxide and water. This reaction releases a lot of heat. Therefore, it is a clean fuel as it does not pollute the air.) Other example: 2C₃H₇OH + 9O₂ –> 6CO₂ + 8H₂O
• Oxidation of ethanol In the laboratory, two common oxidising agents are used for the oxidation of ethanol which are acidified potassium dichromate(VI) solution (orange to green) and acidified potassium manganate(VII) solution (purple to colourless). C₂H₅OH + 2[O] –> CH₃COOH + H₂O Ethanol oxidised to ethanoic acid (a member of the homologous series of carboxylic acids – will be discussed in Part 6). Other example: C₃H₇OH + 2[O] –> C₂H₅COOH + H₂O
• Removal of water (Dehydration) Alcohol can change to alkene by removal of water molecules (dehydration). It results in the formation of a C=C double bond. C_nH_2n+1OH –> C_nH_2n + H₂O C₂H₅OH –> C₂H₄ + H₂O Two methods are being used to carry out a dehydration in the laboratory. a) Ethanol vapour is passed over a heated catalyst such as aluminium oxide, unglazed porcelain chips, pumice stone or porous pot. b) Ethanol is heated under reflux at 180°C with excess concentrated sulphuric acid, H₂SO₄. Other example: C₃H₇OH –> C₃H₆ + H₂O

6. Uses of Alcohol

• Alcohol as a solvent (cosmetics, toiletries, thinners, varnishes, perfumes).
• Alcohol as a fuel (fuel for racing car, clean fuel, alternative fuel).
• Alcohol as a source of chemicals (polymer, explosives, vinegar, fiber).
• Alcohol as a source of medical product (antiseptics for skin disinfection, rubbing alcohol).

7. Misuse and Abuse

• Depressant drug
• Alcoholic drinks
• Addictive drug

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Comparing (Similarities and Differences) Properties of Alkanes and Alkenes

1. Comparing (Similarities and Differences) Properties of Alkanes and Alkenes

Physical Properties	Alkanes	Alkenes
Physical state	Physical state changes from gas to liquid when going down the series.	Same with alkanes.
Electrical conductivity.	Do not conduct electricity at any state.	Same with alkanes.
Boiling points and melting points	Low boiling points and melting points (number of carbon atoms per molecule increases).	Same with alkanes.
Density	Low densities (number of carbon atom per molecule increases).	Same with alkanes.
Solubility in water	Insoluble in water (soluble in organic solvent)	Same with alkanes.
Chemical Properties	Alkanes (Substitution reaction)	Alkenes (Addition reaction)
Reactivity	Unreactive	Reactive
Combustion	Burn in air and produce yellow sooty flame.	Burn in air and produce yellow and sootier flame compare to alkanes.
Reaction with bromine solution	No reaction.	Decolourise brown bromine solution.
Reaction with acidified potassium manganate(VII) solution	No reaction.	Decolourise purple acidified potassium manganate(VII) solution.

2. Isomerism
Isomerism – phenomenon that two or more molecules are found to have the same molecular formula but different structural formulae.
Isomerism in alkanes

Molecular formula	Number of isomers	Structure name
CH4	- (no isomer)	Methane
C2H6	- (no isomer)	Ethane
C3H8	- (no isomer)	Propane
C4H10	2	Butane2-methylpropane
C5H12	3	Pentane2-methylbutane2,2-dimethylpropane

Isomerism in alkenes

Molecular formula	Number of isomers	Structure name
C2H4	- (no isomer)	Ethene
C3H6	- (no isomer)	Propene
C4H8	3	But-1-eneBut-2-ene2-methylpropene
C5H10	5	Pent-1-enePent-2-ene2-methylbut-1-ene 3-methylbut-1-ene 2-methylbut-2-ene

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Family of Hydrocarbon – Alkene

Family of Hydrocarbon – Alkene
1. General formula: C_nH_2n
Where n = 2, 3, 4 … (n = number of carbon)
2. Alkenes are unsaturated hydrocarbons which contain one or more carbon-carbon (C = C) double bonds in molecules.
3. The functional group in alkenes is carbon-carbon double (C = C) bond.

Name of alkene	Molecular formula of alkene
Ethene	C2H4
Propene	C3H6
Butene	C4H8
Pentene	C5H10
Hexene	C6H12
Heptene	C7H14
Octene	C8H16
Nonene	C9H18
Decene	C10H20

• Molecular formula is a chemical formula that shows the actual number of atoms of each type of elements present in a molecule of the compound.
  Example: molecular formula of butene is C₄H_2x4 = C₄H₈

4. Physical properties of alkenes

Name	Molecularformula	RMM	Density(g cm-3)	Physical state at 25°C
Ethene	C2H4	28	0.0011	Gas
Propene	C3H6	42	0.0018	Gas
Butene	C4H8	56	0.0023	Gas
Pentene	C5H10	70	0.6430	Liquid
Hexene	C6H12	84	0.6750	Liquid
Heptene	C7H14	98	0.6980	Liquid
Octene	C8H16	112	0.7160	Liquid
Nonene	C9H18	126	0.7310	Liquid
Decene	C10H20	140	0.7430	Liquid

• Solubility in water – all members in alkenes are insoluble in water but soluble in many organic solvent (benzene and ether).
• Density of alkene – the density of water is higher than density of alkene.
  When going down the series, relative molecular mass of alkenes is higher due to the higher force of attraction between molecules and alkene molecules are packed closer together.
• Electrical conductivity – all members in alkenes do not conduct electricity.
  Alkenes are covalent compounds and do not contain freely moving ions.
• Boiling and melting points – all alkenes in general have low boiling points and melting points. Alkenes are held together by weak attractive forces between molecules (intermolecular forces) van der Waals’ force. When going down the series, more energy is required to overcome the attraction. Hence, the boiling and melting points increases.

5. Chemical properties of alkenes

• Reactivity of alkenes
  Alkenes are more reactive (unsaturated hydrocarbon).
  Alkenes have carbon-carbon (C = C) double bonds which is more reactive than carbon-carbon (C-C) single bonds. All the reaction occur at the double bonds.
• Combustion of alkenes
  Complete combustion of hydrocarbons (alkenes)
  C_xH_y + (x + y/4) O₂ –> xCO₂ + y/2 H₂O
  C₂H₄ +        3O₂ –>  2CO₂ +    2H₂O
  (Alkenes burn with sootier flames than alkanes. It is because the percentage of carbon in alkene molecules is higher than alkane molecules and alkenes burn plenty of oxygen to produce carbon dioxide and water) Incomplete combustion occurs when insufficient supply of oxygen
  C₂H₄ + O₂ –> 2C + 2H₂O
  C₂H₄ + 2O₂ –> 2CO + 2H₂O
  (The flame in the incomplete combustion of alkenes is more smoky than alkanes)
• Polymerisation reaction of alkenes
  Polymers are substances that many monomers are bonded together in a repeating sequence.
  Polymerisation is small alkene molecules (monomers) are joined together to form a long chain (polymer).
  nCH₂ = CH₂ –> -(- CH₂ – CH₂ -)-_n
  ethene (monomer)(unsaturated compound) –> polyethene polymer (saturated compound)
  It must be carry out in high temperature and pressure.
• Addition of hydrogen (Hydrogenation)
  Addition reaction is atoms (or a group of atoms) are added to each carbon atom of a carbon-carbon multiple bond to a single bond.
  C₂H₄ + H₂ –> C₂H₆ (catalyst: nickel and condition: 200°C)
  Example: margarine (produce from hydrogenation of vegetable oils).
• Addition of halogen (Halogenation)
  Halogenation is the addition of halogens to alkenes (no catalyst of ultraviolet light is needed).
  Alkene + Halogen –> Dihaloalkane
  C₂H₄ + Br₂ –> C₂H₄Br₂
  In this reaction the brown colour of bromine decolourised (immediately) to produce a colourless organic liquid.
  Bromination is also used to identify an unsaturated (presence of a carbon-carbon double bond) organic compound in a chemical test.
• Addition of hydrogen halides
  Hydrogen halides (HX) are hydrogen chlorine, hydrogen bromide, hydrogen iodide and etc. This reaction takes place rapidly in room temperature and without catalyst.
  C_nH_2n + HX –> C_nH_2n+1X
  C₂H₄ + HBr –> C₂H₅Br (Bromoethane)
  (There are two products for additional of hydrogen halide to propene. The products are 1-bromopropane and 2-bromopropane).
• Addition of water (Hydration)
  Alkenes do not react with water under ordinary condition. It can react with a mixture of alkene and steam pass over a catalyst (Phosphoric acid, H₃PO₄). The product is an alcohol.
  C_nH_2n + H₂O –> C_nH_2n+1OH
  C₂H₄ + H₂O –> C₂H₅OH
• Additional of acidified potassium manganate(VII), KMnO₄
  C_nH_2n + [O] + H₂O –> C_nH_2n(OH)₂
  C₂H₄ + [O] + H₂O –> C₂H₅(OH)2
  The purple colour of KMnO₄ solution decolourised immediately to produce colourless organic liquid. Also used to identify the presence of a carbon-carbon double bond in a chemical test.

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IUPAC (International Union of Pure and Applied Chemistry)

A) IUPAC (International Union of Pure and Applied Chemistry) – is used to name organic compound.
Organic compound is divided into three portions which is Prefix + Root + Suffix.

1. Prefix – name of the branch or side chain.
   General formula: C_nH_2n+1 –Where n = 1, 2, 3, … (n = number of carbon)

   Formula	Branch or name  of group
   CH3 -	methyl
   C2H5 -	ethyl
   C3H7 -	propyl
   C4H9 -	butyl
   C5H11 -	pentyl

   
   Alkyl group signifies that it is not part of the main chain.
   Two or more types of branches are present, name them in alphabetical order.
   

   Number of side chain	Prefix
   2	Di-
   3	Tri-
   4	Tetra-
   5	Penta-
   6	Hexa-

   More than one side chains are present, prefixes are used.
2. Root – the parent hydrocarbon (denotes the longest carbon chain).
   

   Number of carbon atoms	Root name
   1	meth-
   2	eth-
   3	prop-
   4	but-
   5	pent-
   6	hex-
   7	hept-
   8	oct-
   9	nan-
   10	dec-

   • The longest continuous (straight chain) carbon chain is selected.
   • Identify the number of carbon.
3. Suffix – functional group.
   

   Homologous series	Functional group	Suffix
   Alkane	- C – C -	-ane
   Alkene	- C = C -	-ene
   Alcohol	– OH	-ol
   Carboxylic acid	– COOH	-oic
   Ester	– COO –	-oate

   Example: 4-methylhept-2-ene.
   Prefix + Root + Suffix

B) Family of Hydrocarbon – Alkane
1. General formula: C_nH_2n+2
Where n = 1, 2, 3, … (n = number of carbon)
2. Each carbon atom in alkanes is bonded to four other atoms by single covalent bonds.
Alkanes are saturated hydrocarbon.

Name of alkane	Molecular formula of alkane
Methane	CH4
Ethane	C2H6
Propane	C3H8
Butane	C4H10
Pentane	C5H12
Hexane	C6H14
Heptane	C7H16
Octane	C8H18
Nonane	C9H20
Decane	C10H22

Molecular formula is a chemical formula that shows the actual number of atoms of each type of elements
present in a molecule of the compound.
Example: molecular formula of butane is C₄H_2´4+2 = C₄H₁₀

Name	Condensed structural formula of alkane
Methane	CH4
Ethane	CH3CH3
Propane	CH3CH2CH3
Butane	CH3CH2CH2CH3
Pentane	CH3CH2CH2CH2CH3
Hexane	CH3CH2CH2CH2CH2CH3
Heptane	CH3CH2CH2CH2CH2CH2CH3
Octane	CH3CH2CH2CH2CH2CH2CH2CH3
Nonane	CH3CH2CH2CH2CH2CH2CH2CH2CH3
Decane	CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3

Structural formula is a chemical formula that shows the atoms of elements are bonded (arrangement of atoms) together in a molecule by what types of bond.
3. Physical properties of alkanes

Name	Molecularformula	RMM	Density(g cm-3)	Physical state at 25°C
Methane	CH4	16	-	Gas
Ethane	C2H6	30	-	Gas
Propane	C3H8	44	-	Gas
Butane	C4H10	58	-	Gas
Pentane	C5H12	72	0.63	Liquid
Hexane	C6H14	86	0.66	Liquid
Heptane	C7H16	100	0.68	Liquid
Octane	C8H18	114	0.70	Liquid
Nonane	C9H20	128	0.72	Liquid
Decane	C10H22	142	0.73	Liquid

Alkanes with more than 17 carbon atoms are solid.

• Solubility in water – all members in alkanes are insoluble in water but soluble in many organic solvent (benzene and ether).
• Density of alkane – the density of water is higher than density of alkane.
  When going down the series, relative molecular mass of alkanes is higher due to the higher force of attraction between molecules and alkane molecules are packed closer together.
• Electrical conductivity – all members in alkanes do not conduct electricity.
  Alkanes are covalent compounds and do not contain freely moving ions.
• Boiling and melting points – all alkanes in general have low boiling points and melting points.
  Alkanes are held together by weak intermolecular forces.

4. Chemical properties of alkanes

• Reactivity of alkanes
  Alkanes are less reactive (saturated hydrocarbon).
  Alkanes have strong carbon-carbon (C – C) bonds and carbon-hydrogen (C – H) bonds.
  All are single bonds which require a lot of energy to break.
  Alkanes do not react with chemicals such as oxidizing agents, reducing agents, acids and alkalis.
• Combustion of alkanes
  Complete combustion of hydrocarbons
  C_xH_y + (x + y/4) O₂ –> xCO₂ + y/2 H₂O
  CH₄ +        2O₂ –>  CO₂ +    2H₂OIncomplete combustion
  occurs when insufficient supply of oxygen
  CH₄ + O₂ –> C + H₂O
  2CH₄ + 3O₂ –> 2CO + 4H₂O
• Substitution reaction of alkanes (Halogenation)
  Substitution reaction is one atom (or a group of atoms) in a molecule is replaced by another atom (or a group of atoms).
  Substitution reaction of alkanes take place in ultraviolet light.
  Example:
  Alkanes react with bromine vapour (or chlorine) in the presence of UV light.
  CH₄ + Cl₂ –> HCl + CH₃Cl (Chloromethane)
  CH₃Cl + Cl₂ –> HCl + CH₂Cl₂ (Dichloromethane)
  CH₂Cl₂ + Cl₂ –> HCl + CHCl₃ (Trichloromethane)
  CHCl₃ + Cl₂ –> HCl + CCl₄ (Tetrachloromethane)
  The rate of reaction between bromine and alkanes is slower than the rate of reaction between chlorine and alkanes.

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Carbon Compounds

1. Organic compounds – carbon containing compounds with covalent bonds.
2. Inorganic compounds – non-living things and usually do not contain carbon but few carbon containing inorganic compounds such as CO₂, CaCO₃ and KCN.
3. Hydrocarbons – organic compounds that contain hydrogen and carbon atom only.
4. Non-hydrocarbons – organic compounds that contain other elements (oxygen, nitrogen, iodine, phosphorus)
5. Saturated hydrocarbons – only single bonded (Carbon-Carbon) hydrocarbons.
6. Unsaturated hydrocarbons – at least one double / triple bonded (Carbon-Carbon) hydrocarbons.
7. Complete combustion – organic compounds burn completely which form CO₂ and H₂O.
   Example: C₂H₅OH (l) + O₂ (g) –> 2CO₂ (g) + 3H₂O (l)
8. Incomplete combustion – organic compounds burn with limited supply of O₂ which form C (soot), CO, CO₂ and H₂O.

Homologous Series
Homologous series – organic compounds with similar formulae and properties. It have the physical properties that change gradually as the number of carbon atoms in a molecule increases.

Carbon Compounds	General Formula		Functional group
Alkane	CnH2n+2	n = 1, 2, 3, …	Carbon-carbon single bond - C – C -
Alkene	CnH2n	n = 2, 3, 4, …	Carbon-carbon double bond - C = C -
Alkynes	CnH2n-2	n = 2, 3, 4, …	Carbon-carbon triple bond - C = C -
Arenes	CnH2n-6	n = 6, 7, 8, …	- C = C - delocalised / free to move around the ring
Alcohol	CnH2n+1OH	n = 1, 2, 3, …	Hydroxyl group - OH
Carboxylic Acids	CnH2n+1COOH	n = 0, 1, 2	Carboxyl group - COOH
Esters	CnH2n+1COOCmH2m+1	n = 0, 1, 2, … m = 1, 2, 3, …	Carboxylate group - COO -

Sources of Hydrocarbon:
1.         Coal – from the lush vegetation that grew in warm shallow coastal swamps or dead plants slowly become rock. Mainly contains of hydrocarbon and some sulphur and nitrogen. It is used to produce: fertiliser, nylon, explosives and plastics.
2.         Natural gas – from plants and animals and trapped between the layers of impervious rocks (on top of petroleum). Mainly contains of methane gas and other gas such as propane and butane. It is used for: cooking, vehicle and generate electrical power.
3.         Petroleum – from plants and animals and trapped between the layers of impervious rocks. It is a complex mixture of alkanes, alkenes, aromatic hydrocarbons and sulphur compound. These compounds can be separated by using fractional distillation.

• < 35°C – petroleum gas
• 35°C – 75°C – Petrol (gasoline)
• 75°C – 170°C – Naphtha
• 170°C – 230°C – Kerosene
• 230°C – 250°C – Diesel
• 250°C – 300°C – Lubricating oil
• 300°C – 350°C – Fuel oil
• > 350°C – Bitumen

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