question_answer

In which of the following case, increase in concentration of ion cause increase in\[{{E}_{cell}}\]?

A) \[Pt({{H}_{2}})|{{H}^{+}}(aq)\]

B) \[Pt|Quinhydrone|{{H}^{+}}(aq)\]

C) \[Ag|A{{g}^{+}}(aq)\]

D) \[Ag,\,\,AgCl|C{{l}^{-}}(aq)\]

Correct Answer: D

Solution :

(a)          \[\frac{1}{2}{{H}_{2}}(g)\xrightarrow{{}}{{H}^{+}}(aq)+{{e}^{-}}\]                 \[{{E}_{cell}}=E_{cell}^{o}-0.0591\log [{{H}^{+}}]\] (b)                 \[{{E}_{cell}}=E_{cell}^{o}-0.0591\log {{[{{H}^{+}}]}^{2}}\] (c)\[Ag(s)\xrightarrow{{}}A{{g}^{+}}(aq)\]                 \[{{E}_{cell}}=E_{cell}^{o}-0.0591\log [A{{g}^{+}}]\] (d)\[Ag(s)+C{{l}^{-}}(aq)\xrightarrow{{}}AgCl(s)+{{e}^{-}}\]                 \[{{E}_{cell}}=E_{cell}^{o}-0.0591\,\,\log \frac{1}{[C{{l}^{-}}]}\] Thus, in case (d), the\[{{E}_{cell}}\]increases with increase in the concentration of cell.