Question

For a reaction $A ( s )+2 B ^{\oplus} \rightarrow A ^{2+}+2 B$
$K_{ c }$ has been found to be $10^{12}$. The $E_{\text {cell }}^{\ominus}$ is

• A. $0.354\, V$
• B. $0.708\, V$
• C. $0.0098\, V$
• D. $1.36 \,V$

Answer 1

Answer: (A)

$E=E^{\ominus}-\frac{0.059}{2} \log \,K$
At equilibrium, $E=0$
$E^{\ominus}=\frac{0.059}{2} \log \,K=\frac{0.059}{2} \log 10^{12}$
$=\frac{0.059}{2} \times 12=0.354$