Q. The standard emf for the given cell reaction, $Zn + {Cu}^{2 +} \rightarrow Cu + {Zn}^{2 +}$ is 1.10 V at $25℃$. The emf for the cell reaction, when $0.1\ M\ Cu^{2 +}$ and $0.1\ M\ Zn^{2 +}$ solutions are used, at $25℃$, is
A) 1.10 V
B) $- 1.10\ V$
C) 2.20 V
D) $- 2.20\ V$
Explanation
(a)
$E_{cell} = E_{cell}^{{^\circ}} - \frac{0.059}{n}\log\frac{\left\lbrack {Zn}^{2 +} \right\rbrack}{\left\lbrack {Cu}^{2 +} \right\rbrack}$
$= 1.10 - \frac{0.059}{2}\log\frac{0.1}{0.1}$
$= 1.10\ V$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.