AIIMS2018Chemistry-Electrochemistry

AIIMS 2018 Chemistry Salt Bridges MCQ Question

Type: MCQ-conceptual-Medium-Class 12

Assertion : KCl/NaCl/NH4Cl\text{KCl/NaCl/NH}_4\text{Cl} etc. cannot be used in the salt bridge of a cell containing silver.

Reason : A salt bridge contains concentrated solution of an inert electrolyte like KCl\text{KCl}, KNO3\text{KNO}_3, NH4NO3\text{NH}_4\text{NO}_3 etc. or solidified solution of such an electrolyte in agar-agar and gelatine.

A

If both assertion and reason are true and reason is the correct explanation of assertion.

B

If both assertion and reason are true but reason is not the correct explanation of assertion.

C

If both assertion and reason are false.

D

If both assertion and reason are false.

Correct Answer

Option B

Detailed Explanation

Option B is correct because KCl, NaCl, and NH₄Cl contain chloride ions (Cl⁻), which can react with silver ions (Ag⁺) in the electrochemical cell to form insoluble silver chloride (AgCl) precipitate. This precipitation disrupts the ionic flow necessary for maintaining electrical neutrality in the cell, thereby impairing its function. Other options are not provided, but any salts that do not release Cl⁻ ions when dissolved would be suitable for use as a salt bridge, as they would not form a precipitate with Ag⁺. Understanding the compatibility of ions in electrochemical cells is crucial for effective cell design and operation.

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