Question

Saturated solution of $E_{cell} = Eº_{cell} - \frac{0.0591}{2}\log\frac{\lbrack Fe^{2 +}\rbrack\lbrack H_{2}\rbrack}{\lbrack Fe\rbrack\lbrack H^{+}\rbrack^{2}}$ is used to make ‘salt-bridge’ because.

• A. Velocity of $E_{cell} = Eº_{cell} - \frac{0.0591}{2}\log\frac{\lbrack Fe\rbrack\lbrack H_{2}\rbrack}{\lbrack Fe^{2 +}\rbrack\lbrack H^{+}\rbrack^{2}}$ is greater than that of $Pt_{(s)}|Br_{2(l)}|Br^{- 1}(M)|H^{+}(M)|H_{2(g)}(1bar)|Pt_{(s)}$
• B. Velocity of $E_{cell} = Eº_{cell} - \frac{0.0591}{2}\log\frac{\lbrack Br_{2(l)}\rbrack\lbrack H_{2}\rbrack}{\lbrack H^{+}\rbrack^{2}\lbrack Br^{-}\rbrack^{2}}$ is greater than that of $E_{cell} = Eº_{cell} - \frac{0.0591}{2}\log\frac{\lbrack H^{+}\rbrack^{2}\lbrack Br^{-}\rbrack^{2}}{\lbrack Br_{2(l)}\rbrack\lbrack H_{2}\rbrack}$
• C. Velocities of both $E_{cell} = Eº_{cell} - \frac{0.0591}{2}\log\frac{\lbrack H^{+}\rbrack^{2}\lbrack H_{2}\rbrack}{\lbrack Br_{2(l)}\rbrack\lbrack Br^{-}\rbrack^{2}}$and $E_{cell} = Eº_{cell} - \frac{0.0591}{2}\log\frac{\lbrack Br_{2(l)}\rbrack\lbrack Br^{-}\rbrack^{2}}{\lbrack H^{+}\rbrack^{2}\lbrack H_{2}\rbrack}$ are nearly the same
• D. $Eº_{cell}$is highly soluble in water

Answer 1

Answer: (C)

Velocities of both $E_{cell} = Eº_{cell} - \frac{0.0591}{2}\log\frac{\lbrack H^{+}\rbrack^{2}\lbrack H_{2}\rbrack}{\lbrack Br_{2(l)}\rbrack\lbrack Br^{-}\rbrack^{2}}$and $E_{cell} = Eº_{cell} - \frac{0.0591}{2}\log\frac{\lbrack Br_{2(l)}\rbrack\lbrack Br^{-}\rbrack^{2}}{\lbrack H^{+}\rbrack^{2}\lbrack H_{2}\rbrack}$ are nearly the same

Answer 2

Velocities of both $K^{+}$ and $NO_{3}^{-}$ are nearly the same in $KNO_{3}$ so it is used to make salt-bridge.