Question

Which of the following statements are correct regarding to galvanic cell?

• A. A reaction is spontaneous from left to right if $E_{\text{cell}}>0$
• B. A reaction occurs from right to left if $E_{\text{cell}}<0$
• C. If the system is at equilibrium, no net reaction occurs
• D. $E_{\text{cell}}$ is temperature-independent

Answer 1

Answer: (A), (B), (C)

If the system is at equilibrium, no net reaction occurs

In galvanic cell,
$\underset{\text{(oxidation)}}{\text{Anode}}\stackrel{e^{-}}{\to }\underset{\text{(reduction)}}{\text{Cathode}}$
$E_{\text{cell}}=E_{\text{cell}}^{\circ }-\frac{RT}{nF}lnQ$
(a) For left to right
For spontaneity, $\Delta G<0$
$(\Delta G=-nF{E}_{\text{cell}})$
So, $E_{\text{cell}}<0$

(b) Right $\to$left
$\Delta G>0(-nF{E}_{\text{cell}}>0)$
So, $E_{cell}<0$

(c) At equilibrium,
$E_{\text{cell}}=0\Rightarrow$ So, net reaction occurs.

(d) It is temperature dependent