Which of the following species acts as a reducing agent during the working of a hydrogen-oxygen fuel cell?

Given that $\frac{1}{3} \lambda_m^\infty (Fe^{3+}) = 68 \ \Omega^{-1} \ cm^{2} \ eq^{-1}$ and $\frac{1}{2} \lambda_m^\infty (SO_4^{2-}) = 80 \ \Omega^{-1} \ cm^{2} \ eq^{-1}$. What will be the value of $\lambda_{eq}^\infty (Fe_2(SO_4)_3)$? ............ $\Omega^{-1} \ cm^2 \ eq^{-1}$

Which of the following curves represents the variation of $\lambda_{M}$ with $\sqrt{C}$ for $AgNO_{3}$?

Given the data at $25\, ^oC$:
$Ag + I^{-} \rightarrow AgI + e^-$,$E^o = 0.152\, V$
$Ag \rightarrow Ag^{+} + e^-$,$E^o = -0.800\, V$
What is the value of $\log K_{sp}$ for $AgI$? $(2.303\, RT/F = 0.059\, V)$

The reference electrode,specifically the Saturated Calomel Electrode $(SCE)$,is made from which of the following substances?

During discharging,the change taking place at the cathode in a lead accumulator is: