Question

Calculate the emf of the following cell at $25^{o}C$. $Ag(s)|AgNO_{3}(0.01molkg^{- 1})||AgNO_{3}(0.05molkg^{- 1})|Ag(s)$

• A. – 0.414 V
• B. – 0.828 V
• C. – 0.414 V
• D. – 0.0414 V

Answer 1

Answer: (D)

– 0.0414 V

Answer 2

It is a concentration cell. The emf of a concentration cell is

$E_{\text{cell}} = + \frac{0.0592}{n}\log\frac{C_{1}}{C_{2}}$ at 25^o C and n = 1

$= + 0.0592\log\frac{0.01}{0.05} = 0.0591\log 0.2 = 0.0591 \times ( - 0.699) = - 0.0414$V