The following four solutions are kept in separate beakers and copper metal is put in each of them. Which solution will become blue after some time?

At $298 \ K$ temperature,if $E^o_{Mg^{2+}|Mg} = -2.37 \ V$ and $E^o_{Co^{2+}|Co} = -0.28 \ V$,construct a galvanic cell and provide its symbolic representation.

What advantage do the fuel cells have over primary and secondary batteries?

$Cu^{+}_{(aq)}$ is unstable in solution and undergoes simultaneous oxidation and reduction,according to the reaction $2 Cu^{+}_{(aq)} \rightleftharpoons Cu^{2+}_{(aq)} + Cu_{(s)}$. Choose the correct $E^{\circ}$ for the above reaction if $E^{\circ}_{Cu^{2+}/Cu} = 0.34 \ V$ and $E^{\circ}_{Cu^{2+}/Cu^{+}} = 0.15 \ V$.

Consider the figure and answer the questions $(i)$ to $(vi)$ given below.
$(i)$ Redraw the diagram to show the direction of electron flow.
$(ii)$ Is the silver plate the anode or cathode?
$(iii)$ What will happen if the salt bridge is removed?
$(iv)$ When will the cell stop functioning?
$(v)$ How will the concentration of $Zn^{2+}$ ions and $Ag^{+}$ ions be affected when the cell functions?
$(vi)$ How will the concentration of $Zn^{2+}$ ions and $Ag^{+}$ ions be affected after the cell becomes 'dead'?

In a $Cu-Zn$ cell,.....