Question

Assertion (A): For a Daniell cell, \[\ce{Zn/Zn^2+(1M) || Cu^2+(1M)/Cu}\] with E⁰_cell = 1.1 V, if the external opposing potential is more than 1.1 V, the electrons flow from \[\ce{Cu to Zn}\].

Reason (R): Cell acts like a galvanic cell.

Options

• Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).

• Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).

• Assertion (A) is true, but Reason (R) is false.

• Assertion (A) is false, but Reason (R) is true.

Answer 1

Assertion (A) is true, but Reason (R) is false.

Explanation:

The \[\ce{Zn - Cu}\] Daniel cell will change from being a galvanic cell to an electrolytic cell with the direction of electron flow reversed if the opposing potential (external potential) rises over 1.10 volts. The external potential will cause the electrons to flow in the other direction—from the copper electrode to the zinc electrode—instead of the spontaneous flow from the zinc electrode to the copper electrode.