How much electricity is required to deposit $108 \ g$ of silver from a silver nitrate solution?

How much electricity is required in coulomb for the oxidation of
$(i)$ $1 \, mol$ of $H_2O$ to $O_2?$
$(ii)$ $1 \, mol$ of $FeO$ to $Fe_2O_3?$

An acidic solution of dichromate is electrolyzed for $8 \ min$ using $2 \ A$ current. As per the following equation: $Cr_{2}O_{7}^{2-} + 14H^{+} + 6e^{-} \rightarrow 2Cr^{3+} + 7H_{2}O$. The amount of $Cr^{3+}$ obtained was $0.104 \ g$. The efficiency of the process (in $\%$) is (Take: $F = 96000 \ C$,At. mass of chromium $= 52$)

Copper sulphate solution is electrolysed between two platinum electrodes. $A$ current is passed until $1.6 \ g$ of oxygen is liberated at the anode. The amount of copper deposited at the cathode during the same period is .............. $g$ [At. mass of $Cu = 63.6$]

$A$ $200 \ W, 100 \ V$ bulb is connected in series with an electrolytic cell. If an aqueous solution of an $Sn$-salt is electrolysed for $5 \ hrs$,$11.1 \ g$ of $Sn$ gets deposited. The chemical formula of the compound is (Given atomic weight of $Sn$ is $118.7 \ g \ mol^{-1}$).

How many Coulombs of electricity are required for the oxidation of one mol of water to dioxygen?