ALCOHOLS

• -non-hydrocarbons• Contain hydroxyl group (-OH)• Can derived from an alkene• General formula: CnH2n+1OH

NAMING ALCOHOLS

1. Obtain the name of alkane2. Replace the ending –e from alkane with –ol3. Example: methane : methanol

Draw:1. Ethanol2. Propan-1-ol3. Butan-1-ol4. Butan-2-ol

ISOMERS OF ALCOHOL

Draw the isomers and name these alcohols:• C3H7OH (2 isomers)

• C4H9OH (4 isomers)

INDUSTRIAL PRODUCTION OF ETHANOL

1. By fermentation- Yeast is added to sugar or starch and left in a warm place for

several days in the absence of oxygen (anaerobic)

C6H12O6 2 CH3CH2OH + 2 CO2

Glucose Ethanol + carbon dioxide

Temperature : 18-200CCatalyst : zymase from yeastOther condition: Absence of oxygen

*ethanol then purified by fractional distillation

2. By hydration

ethene + water ethanolCH2=CH2 + H2O CH3CH2OH

temperature : 3000Cpressure :60 atmCatalyst : phosphoric acid

PHYSICAL PROPERTIES OF ALCOHOLS

• Liquid at room condition• Colourless• Has a sharp smell• Completely miscible in water• Low boiling point• Highly volatile

CHEMICAL PROPERTIES OF ETHANOL1. Combustion

- Complete combustion, produce carbon dioxide and water- C2H5OH + 3 O2 2 CO2 + 3 H2O

2. Oxidation- Alcohols can easily oxidised to carboxylic acids, (-COOH group) with presence of

oxidising agents such as acidified potassium dichromate (VI) solution and acidified potassium manganate (VII) solution

- acidified potassium dichromate (VI) solution: orange to green- acidified potassium manganate (VII) solution: purple to colourless

CH3CH2OH + 2[O] CH3COOH + H2O

3. Dehydration- Involve removal of water- Ethanol ethene + water (draw!!)- Two methods to carry out :

(a) Ethanol is passed over a heated catalyst such as unglazed porcelain chips, porous pot, pumice stone, or aluminium oxide

(b) Ethanol is heated under reflux at 1700C with excess concentrated sulphuric acid

USES OF ALCOHOLS

• As a solvent in perfumes/cosmetics• As a thinner in varnish, ink• As a cleaner for compact disc.• As a fuel for transport• As a raw material for the manufacture of

vinegar,• As a raw material to make industrial product

such as antiseptic and cough syrup.

CARBOXYLIC ACIDS

• General formula: CnH2n+1COOH• -COOH group is called carboxyl group as the

functional group of carboxylic acid• Naming for carboxylic acid:

~anol change to ~anoic acidExample: methanol : methanoic acid

STRUCTURAL FORMULA

• Draw the structural formula for:– Methanoic acid

– Ethanoic acid

• Propanoic acid

• Butanoic acid

• 2-methylpropanoic acid

• 3-methylpentanoic acid

Preparation of ethanoic acid

• Heating the mixture of ethanol and acidified potassium dichromate (VI), K2Cr2O7 under reflux (oxidation reaction)

• C2H5OH + 2[O] CH3COOH + H2OEthanol ethanoic acid

Physical Properties of Ethanoic Acid

• Colourless liquid at room temperature• Has a sharp and pungent smell• High melting and boiling point compare to

other covalent• Soluble in water• Changes the moist blue litmus paper to red• Has a pH of 3-4 (weak acid)

Chemical Properties of Ethanoic Acid

• Ethanoic acid is a weak acid. Ethanoic acid can ionized partially in water to produce low concentration of hydrogen ion, H+

• Weak monoprotic acid• Ethanoic acid can react with:– Base– Metal carbonate– Metal– Alcohol

i) REACTION OF ETHANOIC ACID WITH A BASE (neutralization)

CH3COOH + NaOH CH3COONa

ethanoic acid sodium ethanoate

ii) REACTION OF ETHANOIC ACID WITH METAL CARBONATE

CH3COOH + CaCO3 (CH3COO)2Ca + H2O + CO2

ethanoic acid calcium ethanoate

ii) REACTION OF ETHANOIC ACID WITH METAL

CH3COOH + Mg (CH3COO)2Mg + H2

ethanoic acid magnesium ethanoate

Iv) REACTION OF ETHANOIC ACID WITH ALCOHOL (esterification)CH3COOH + c2H5OH CH3COOC2H5 + H2

ethanoic acid ethyl ethanoate

USES OF CARBOXYLIC ACIDS• Carboxylic acid widely found in nature

Ethanoic acid (acetic acid) : VinegarMethanoic acid : AntsPropanoic acid : MilkButanoic acid : ButterLactic acid : Sour milk

• Uses of carboxylic acidi- make food flavouringii- preserve foodiii- manufacture foods such as vinegar and yogurtiv- manufacture of soft drinks

34ETHANOIC ACID,CH3COOH

Sodium ethanoate,CH3COONa

+Hydrogen, H2

Iron (III) ethanoate,

Fe(CH3COO)3

+Carbon dioxide,

CO2

+ Water, H2O

Calcium ethanoate,Ca(CH3COO)2

+ Water, H2O

Methyl ethanoate, CH3COOCH3

+Water, H2O

Base, Ca(OH)2

Metal, Na

Alcohol, CH3OH

Metal carbonate, Fe2(CO3)3