UPSC Prelims 2009 Q65: Science & Technology – Energy & Environment

UPSC Prelims 2009, General Studies Paper I · Science & Technology

In a dry cell (battery), which of the following are used as electrolytes?

Answer: (a) Ammonium chloride and Zinc chloride

Explanation

Electrolytes used in a dry cell battery

A standard dry cell relies on specific chemical compounds to function as its electrolyte.

Option	Verdict	Reason
(a) Ammonium chloride and Zinc chloride	Correct	A typical dry cell uses a paste of ammonium chloride and zinc chloride as its electrolyte
(b) Sodium chloride and Calcium chloride	Incorrect	These are not the standard dry cell electrolytes
(c) Magnesium chloride and Zinc chloride	Incorrect	Magnesium chloride is not part of the standard dry cell formulation
(d) Ammonium chloride and Calcium chloride	Incorrect	Calcium chloride is not the correct pairing here

Dry cell electrolyte facts:

Point	Detail
Electrolyte paste	Ammonium chloride + Zinc chloride
Cell type	Leclanché dry cell

Answer: (a) Ammonium chloride and Zinc chloride.

(a) CORRECT. Ammonium chloride and zinc chloride form the standard dry cell electrolyte paste.
(b) Incorrect. Sodium chloride and calcium chloride are not this electrolyte's components.
(c) Incorrect. Magnesium chloride is not part of the standard formulation.
(d) Incorrect. Calcium chloride is not the correct pairing.

A standard dry cell uses a paste of AMMONIUM CHLORIDE and ZINC CHLORIDE as its electrolyte.

Dry cell batteries use ammonium chloride and zinc chloride as the electrolyte.

Confusing the dry cell's actual electrolyte (ammonium + zinc chloride) with other chloride compounds.
Not knowing the specific Leclanché cell chemistry behind common dry cell batteries.
Mixing up different battery chemistries' specific electrolyte formulations.

Dry cell (Leclanché) electrolyte = ammonium chloride + zinc chloride. A specific battery-chemistry fact.