In the cell represented as $Ni_{(s)}|Ni_{(1M)}^{2+}||Ag_{(1M)}^{+}|Ag_{(s)}$,the reducing agent is

Which substance is used as an oxidising agent in a nickel-cadmium cell?

The Gibbs energy change (in $J$) for the given reaction at $[Cu^{2+}] = [Sn^{2+}] = 1 \, M$ and $298 \, K$ is:
$Cu_{(s)} + Sn^{2+}_{(aq)} \rightarrow Cu^{2+}_{(aq)} + Sn_{(s)}$
$(E^{\circ}_{Sn^{2+}|Sn} = -0.16 \, V, E^{\circ}_{Cu^{2+}|Cu} = 0.34 \, V, F = 96500 \, C \, mol^{-1})$

Calculate $\Delta_r G^o$ for the cell reaction:
$Zn_{(s)} + Cu^{2+}_{(aq)} \to Zn^{2+}_{(aq)} + Cu_{(s)}$
Given: $E^o_{Cu^{2+}/Cu} = 0.34 \, V, E^o_{Zn^{2+}/Zn} = -0.76 \, V$

Which of the following statements are correct regarding a fuel cell that uses hydrogen and oxygen as fuels?
$A$. It has been used in spaceships.
$B$. It has an efficiency of about $40 \%$ to $60 \%$ to produce electricity.
$C$. It uses aluminium as a catalyst.
$D$. It is eco-friendly.
$E$. It is actually a type of galvanic cell.

While charging the lead storage battery,