Assertion `(A) :` In a Daniell cell, if the concentration of `Cu^(2+)` and `Zn^(2+)` ions are doubled, the `EMF` of the cell will be doubled.
Reason `(R) :` If the concentration of ions in contact with metals is doubled, the electrode potential is doubled.

Options

A. If both assertion and reason are true, and reason is the true explanation of the assertion
B. if both assertion and reason are true, but reason is not the true explanation of the assertion.
C. if assertion is true, but reason is false.
D. If both assertion and reason are false.

Answer

D

Explanation

Correct A. `Zn+Cu^(2+)toZn^(2+)+Cu,E_(cell)=E_(cell)^(@)-(RT)/(nF)"ln"([Zn^(2+)])/([Cu^(2+)])`
Thus, if `[Zn^(2+)]` and `[Cu^(2+)]` are doubled, there is no effect of emf.
Correct R. `Cu^(2+)+2e^(-)toCu,E=E^(@)-(RT)/(nF)"ln"(1)/([Cu^(2+)])`
Thus, if `[C^(2+)]` is doubled, E is not doubled.