Ethanol or Ethyl alcohol
This is obtained by the fermentation of Molasses in the presence of enzymes as catalyst.
C12H22O11+H2O→C6H12O6 + C6H12O6
(sugar) (glucose) (fructose)
Properties of ethyl alcohol
This can be also obtained by the hydration of ethylene.
Physical properties
It is a colorless liquid with a characteristic alcoholic smell.
Its boiling point is 351K
It is neutral towards litmus paper
It is highly soluble in water.A solution of 95% alcohol and 5% water is called as rectified spirit. Completely pure 100% alcohol is called absolute alcohol.
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Chemical Properties
Ethanol reacts with sodium in the cold to form sodium ethoxide with the evolution of hydrogen gas
2CH3CH2OH + 2Na →2CH3CH2ONa +H2
Ethanol reacts with concentrated sulphuric acid at 443K to give the unsaturated ethene.
CH3CH2OH →C2H4 + H2O
This reaction is also called as dehydration reaction because it involves the removal of a molecule of water from ethanol.
Uses of Ethanol
Ethanol in form of rectified spirit (95% alcohol and 5% water) is used as an antiseptic for wounds. It is also used for sterlizing skin before gibing an injection.
Ethanol is used in alcoholic beverages
Ethanol is widely used in industry as a solvent for paints, lacquers, tincture iodine, cough syrups, perfumes, etc.
Ethanol is used in the preparation of dyes, cosmetics and transparent soaps.
It is used in the many other chemicals such as chloroform, iodoform, ether, acetic acid, acetaldehyde etc.
It is used as a fuel in internal combustion engines in form of power alcohol
In cold countries it is used as an antifreeze in the radiators of automobiles.
It is used in spirit levels and low temperature thermometers.
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Ethanoic Acid
? Physical properties:
? Ethanoic acid is a colourless, pungent smelling liquid.
? When pure ethanoic acid is cooled, it freezes forming glacire like crystals, which is called glacial acetic acid
? It is miscible with water in all proportions.
Chemical Properties
? 1.Active metals like sodium, pottasium, calcium, magnesium etc which all lie above hydrogen in reactive series react with ethanoic acid evolving hydrogen gas to form metal salts .
? 2CH3COOH +2Na → 2CH3COONa +H2
? 2. Ethanoic acid reacts with bases like sodium hydroxide to give a salt and water.
? CH3COOH + NaOH →CH3COONa + H2O
? 3. It reacts with sodium carbonate and sodium hydrogen carbonate to give sodium ethanoate and water with the evolution of carbon dioxide
? CH3COOH +Na2CO3 → CH3COONa + H2O+CO2
? CH3COOH +NaHCO3 → CH3COONa + H2O+CO2
? 4. Esterification:When ethanoic acid is warmed with ethanol in presence of a few drops of concentrated sulphuric acid as catalyst, an ester (ethyl ethanoate) and water are formed
? CH3COOH+ CH3CH2OH → CH3COO CH2CH3 + H2O
? (Conc.H2SO4)
? 5. Esters, on heating with an aqueous acid or a base gives back the original alcohol and acid.
? CH3COO CH2CH3 + NaOH → CH3COONa + CH3CH2OH
? CH3COO CH2CH3+ H2O→ CH3COOH + CH3CH2OH