Question

$P t(s)\left|II_2( g )(1 bar )\right| II^{+}(a q)(1 M)|| M^{3+}(a q), M^{+}(a q) \mid P t(s)$ The $E _{\text {cell }}$ for the given cell is $01115 V$ at $298 K$ when $\frac{\left[M^{+}(a q)\right]}{\left[M^{3+}(a q)\right]}=10^{\circ}$ The value of $a$ is _____ Given : $E ^\theta M ^{3+} M ^{+}=02 V$ $\frac{2303 R T}{F}=0059 V$

Answer 1

The correct answer is 3.
Overall reaction :-
H2(g)​+M(aq) 3+​>M(aq) +​+2H(aq) +​
ECell ​=ECathode o​−Eanode ∘​−20.059​log[M+3]1[M+]×12​
0.1115=0.2−20.059​log[M+3][M+]​
3=log[M+3][M+]​
∴a=3