Faraday's laws of electrolysis will fail when

How much electricity in terms of Faraday is required to produce $2.7 \ g$ of $Al$ from molten $Al_2O_3$? (Atomic mass of $Al = 27 \ u$)

During the electrolysis of concentrated $H_2SO_4$,perdisulphuric acid $(H_2S_2O_8)$ and $O_2$ are formed in equimolar amounts. The amount of $H_2$ that will be formed simultaneously is $(2H_2SO_4 \rightarrow H_2S_2O_8 + 2H^+ + 2e^-)$

Equal amounts of electricity are passed through two separate electrolytic cells containing nickel nitrate $[Ni(NO_3)_2]$ and chromium nitrate $[Cr(NO_3)_3]$. If $0.3 \ g$ of nickel is deposited in the first cell,how much chromium will be deposited in the second cell? (Atomic mass of $Ni = 59$,Atomic mass of $Cr = 52$)

In acidic medium,$MnO_4^-$ is converted to $Mn^{2+}$ when it acts as an oxidant. The quantity of electricity required to reduce $0.06 \ mol$ of $MnO_4^-$ would be ........... $F$.

$A$ $200 \ W, 100 \ V$ 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 $118.7 \ g \ mol^{-1}$).