Question

If one mole electrons is passed through the solutions of $Al Cl _{3}, AgNO _{3}$ and $MgSO _{4}$, in what ratio $Al , Ag$ and $Mg$ will be deposited at the electrodes?

• A. $3: 6: 2$
• B. $2: 6: 3$
• C. $1: 2: 3$
• D. $3: 2: 1$

Answer 1

Answer: (B)

$e q_{A l}=e q_{A g}=e q_{M g}$
eq $=$ moles $\times n -$ factor
$A l^{+3}+3 e^{-} \rightarrow A l$
$A g^{+}+e^{-} \rightarrow A g$
$M g^{+2}+2 e^{-} \rightarrow M g$
$\frac{1}{3} mol \,Al : 1 \,mol \,Ag : \frac{1}{2} mol \,Mg$
or $2: 6: 3$