Ethanol
(i) Ethanol, C2H5OH is a colourless liquid having a pleasant smell.
(ii) It boils at 351 K.
(iii) It is miscible with water in all proportions.
(iv) It is a nonconductor of electricity (it does not contain ions)
(v) It is neutral to litmus.
Uses:
1. As an antifreeze in radiators of vehicles in cold countries.
2. As a solvent in the manufacture of paints, dyes, medicines, soaps and synthetic rubber.
3. As a solvent to prepare the tincture of iodine.
How Do Alcohols Affect Human Beings?
(i) If ethanol is mixed with CH3OH and consumed, it causes serious poisoning and loss of eyesight.
(ii) It causes addiction, damages the liver if taken in excess.
(iii) High consumption of ethanol may even cause death.
Reactions of Ethanol with Sodium
Ethanol reacts with sodium to produce hydrogen gas and sodium ethoxide. This reaction supports the acidic character of ethanol.
2C2H5OH+2Na → 2C2H5ONa+H2(↑)
Elimination Reaction
An elimination reaction is a type of reaction in which two substituents are removed from a molecule. These reactions play an important role in the preparation of alkenes.
Dehydration Reaction
Ethanol reacts with concentrated sulphuric acid at 443 K to produce ethylene. This reaction is known as dehydration of ethanol because, in this reaction, a water molecule is removed from the ethanol molecule.
CH3CH2OH → CH2=CH2+H2O
(reaction taking place in presence of Conc.H2SO4)
Ethanoic Acid or Acetic Acid
(i) Molecular formula: CH3COOH
(ii) It dissolves in water, alcohol and ether.
(iii) It often freezes during winter in cold climate and therefore it is named as glacial acetic acid.
Esterification
When a carboxylic acid is refluxed with alcohol in the presence of a small quantity of conc.H2SO4, a sweet-smelling ester is formed. This reaction of ester formation is called esterification.
When ethanol reacts with ethanoic acid in presence of conc.H2SO4, ethyl ethanoate and water are formed.
CH3COOH+C2H5OH → CH3COOC2H5+H2O
(reaction taking place in presence of Conc.H2SO4)
Saponification
A soap is a sodium or potassium salt of long-chain carboxylic acids (fatty acid). The soap molecule is generally represented as RCOONa, where R = non-ionic hydrocarbon group and −COO−Na+ ionic group. When oil or fat of vegetable or animal origin is treated with a concentrated sodium or potassium hydroxide solution, hydrolysis of fat takes place; soap and glycerol are formed. This alkaline hydrolysis of oils and fats is commonly known as saponification.
Reaction of Ethanoic Acid with Metals and Bases
Ethanoic acid (Acetic acid) reacts with metals like sodium, zinc and magnesium to liberate hydrogen gas.
2CH3COOH+2Na→2CH3COONa+H2(↑)
It reacts with a solution of sodium hydroxide to form sodium ethanoate and water.
CH3COOH+NaOH→CH3COONa+H2O
Reaction of Ethanoic Acid with Carbonates and Bicarbonates
Carboxylic acids react with carbonates and bicarbonates with the evolution of CO2 gas. For example, when ethanoic acid (acetic acid) reacts with sodium carbonate and sodium bicarbonate, CO2 gas is evolved.
2CH3COOH+Na2CO3→2CH3COONa+H2O+CO2
CH3COOH+NaHCO3→CH3COONa+H2O+CO2
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