Question

Which of the following statements about a concentration cell is false?

(1)The concentration decreases in the more concentrated half-cell.

(2)Both half-cells are composed of the same species.

(3)E° is always zero in a concentration cell.

(4)The spontaneous reaction is always from the more dilute solution to the more concentrated solution.

(5)The concentration increases in the less concentrated half-cell.

Answer 1

In electrochemistry , the voltage can also be generated if the anodic compartment and the cathodic compartment are of same metal electrode , but the concentrations are different , is called concentration cell .

Since, the anode and cathode electrode are the same,

since , E⁰ cell = E⁰ cathode – E⁰ anode

so, E⁰ cell = 0

The working of concentration cell involves the movement of solution from higher concentration towards lower concentration.

This is done by the transference of the electrons from the cell with lower concentration to higher concentration.

From the question,

option (1) and (5) are correct,

Reason,

reaction will proceed from higher concentration cell towards less concentration cell,

thereby, the more concentration half cell – concentration decrease

and the less concentration half cell – concentration increase

Option (2) is correct

The concentration cell me is made up same type electrode.

Option (3) is correct,

The E⁰ cell = 0 , for the concentration cell.

Option (4) is incorrect,

The spontaneous reaction , is from more concentrated solution towards less concentrated solution .