Calculate current in ampere required to deposit $$4.8 \mathrm{~g} ~\mathrm{Cu}$$ from it's salt solution in 30 minutes. [Molar mass of $$\mathrm{Cu}=63.5 \mathrm{~g} \mathrm{~mol}^{-1}$$ ]

Identify the gas produced due to reduction of $$\mathrm{NH}_4^{+}$$ ions at cathode during working of dry cell.

How long will it take to produce $$5.4 \mathrm{~g}$$ of $$\mathrm{Ag}$$ from molten $$\mathrm{AgCl}$$ by passing $$5 \mathrm{~amp}$$ current?

(Molar mass Ag = $$108 \mathrm{~g} \mathrm{~mol}^{-1}$$ )

Which of the following is NOT an example of secondary voltaic cell?