Match List-I with List-II.
| List-I | List-II |
|---|---|
| (A) Invertase | (I) Makes commercial alcohol unfit for drinking |
| (B) Zymase | (II) Ferments glucose and fructose to ethanol |
| (C) Oxygen of air entering the fermentation mixture | (III) Converts the sugar of molasses into glucose and fructose |
| (D) Copper sulphate and pyridine | (IV) Oxidises ethanol to ethanoic acid |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → A-III, B-II, C-IV, D-I
Ethanol is obtained commercially by fermentation of sugars. Two enzymes act one after the other, and the process must be kept free of air.
(A) Invertase — This matches (III) Converts the sugar of molasses into glucose and fructose. Invertase acts first, on the sugar of molasses, sugarcane or fruits.
(B) Zymase — This matches (II) Ferments glucose and fructose to ethanol. Zymase is found in yeast; its action stops once the alcohol formed exceeds 14 percent.
(C) Oxygen of air entering the fermentation mixture — This matches (IV) Oxidises ethanol to ethanoic acid. Fermentation is anaerobic; the acid formed by air spoils the taste of alcoholic drinks.
(D) Copper sulphate and pyridine — This matches (I) Makes commercial alcohol unfit for drinking. Copper sulphate gives a colour and pyridine a foul smell; this is the denaturation of alcohol.
NCERT (2026-27 edition):
7.5 Some Commercially Important Alcohols – “…The sugar in molasses, sugarcane or fruits such as grapes is converted to glucose and fructose, (both of which have the formula C6H12O6), in the presence of an enzyme, invertase. Glucose and fructose undergo fermentation in the presence of another enzyme, zymase, which is found in yeast.”
“…If air gets into fermentation mixture, the oxygen of air oxidises ethanol to ethanoic acid which in turn destroys the taste of alcoholic drinks.”
“…The commercial alcohol is made unfit for drinking by mixing in it some copper sulphate (to give it a colour) and pyridine (a foul smelling liquid). It is known as denaturation of alcohol.”