Question

Assertion :In the Daniell cell, if concentrations of $C{u}^{2+}$ and $Z{n}^{2+}$ ions are doubled, the emf of the cell will be doubled. Reason: If the concentration of ions in contact with the metals is doubled, the electrode potential is doubled.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Assertion is incorrect but Reason is correct

Answer 1

The correct option is D Assertion is incorrect but Reason is correct

In Daniell cell, the cell emf is directly proportional to the ratio of the concentration of the $C{u}^{2+}$ and $Z{n}^{2+}$;

so, on increasing the concentration of both ions, the ratio will remain constant and hence the emf will also be constant;

but electrode potential is directly proportional to the concentration of metal ion;

so, assertion is incorrect but the reason is correct.