$96500 \ C$ of electric charge liberates how many grams of $Cu$ from $CuSO_4$ solution?

$38.6 \ A$ of current is passed for $100 \ s$ through an aqueous $CuSO_4$ solution using platinum electrodes. The mass of copper deposited from the solution and the volume of gas liberated at $STP$ are respectively (molar mass of $Cu = 63.54 \ g \ mol^{-1}$)

Consider the reaction: $Cr_{2}O_{7}^{2-} + 14H^{+} + 6e^{-} \rightarrow 2Cr^{3+} + 7H_{2}O$. What is the quantity of electricity in coulombs needed to reduce $1 \ mol$ of $Cr_{2}O_{7}^{2-}$?

In order to separate oxygen from one mole of $H_2O$,the required quantity of electricity in coulombs is:

Two electrolytic cells,one containing acidified ferrous chloride $(FeCl_2)$ and the other containing acidic ferric chloride $(FeCl_3)$,are connected in series. When an electric current is passed through the cells,what is the ratio of iron deposited at the cathodes in the two cells?

To deposit a silver layer of thickness $5 \times 10^{-3} \ cm$ on a surface area of $80 \ cm^2$ (density $= 10.5 \ g \ cm^{-3}$),a current of $3 \ A$ is passed through a silver nitrate solution for ......... $sec$.