Calculate the amount of electricity required in coulombs to convert $0.08 \ mol$ of $MnO_4^{-}$ to $Mn^{2+}$. (in $C$)

What is the amount of chlorine evolved when $2 \ A$ of current is passed for $30 \ min$ in an aqueous solution of $NaCl$ (in $g$)?

$250 \ mL$ of a waste solution obtained from the workshop of a goldsmith contains $0.1 \ M \ AgNO_3$ and $0.1 \ M \ AuCl$. The solution was electrolyzed at $2 \ V$ by passing a current of $1 \ A$ for $15 \ minutes$. The metal/metals deposited will be
$(E^0_{Ag^+/Ag} = 0.80 \ V, E^0_{Au^+/Au} = 1.69 \ V)$

Passage of a current for $548 \, s$ through a silver coulometer results in the deposition of $0.746 \, g$ of silver. What is the current (in $A$)?

The electrochemical equivalent of a metal is $x \ g \ C^{-1}$. The equivalent weight of the metal is:

The same quantity of electricity was passed through solutions of salts of elements $X$,$Y$,and $Z$ with atomic masses $7$,$27$,and $48$ respectively. The masses of $X$,$Y$,and $Z$ deposited were $2.1 \ g$,$2.7 \ g$,and $7.2 \ g$ respectively. The valencies of $X$,$Y$,and $Z$ respectively are: