Question: Why does Ethanoic acid called glacial acetic acid? (Imp.)
Ans. On cooling, pure ethanoic acid is frozen to form ice like flakes. They look like glaciers, so it is called glacial acetic acid.
Question: Why is the conversion of ethanol to ethanoic acid an oxidation reaction? (Imp.)
Ans. When ethanol is oxidised, hydrogen is removed from its molecule and oxygen is added so as to form ethanoic acid. Thus, conversion of ethanol into acetic acid is an oxidation reaction.
Question: A mixture of ethyne and oxygen is burnt for welding. Can you tell why a mixture of ethyne and air is not used? (Imp.)
Ans. Ethyne has only two hydrogen atoms and two carbon atoms in its molecule. It burns in air with a sooty flame, because the oxygen from air is insufficient to burn the carbon completely. Thus, pure oxygen is used which completely burns carbon and hydrogen and produces a very hot flame.
Question: Why is the conversion of ethanol to ethanoic acid considered an oxidation reaction?
Ans. Conversion of ethanol to ethanoic acid is considered an oxidation reaction since it involves:
(i) addition of oxygen to the ethanol molecule (ii) removal of hydrogen from the ethanol