Question

$108g$ of silver (molar mass $108g$ $mo{l}^{-1}$ ) is deposited at cathode from $AgN{O}_3$ (aq) solution by a certain quantity of electricity. The volume (in L) of oxygen gas produced at $273K$ and $1$ bar pressure from water by the same quantity of electricity is

• A. $2.82L$
• B. $5.675L$
• C. $1.41L$
• D. $0.746L$

Answer 1

Answer: (B)

$[n_{Ag}{]}_{deposit}=\frac{108}{108}=1$ $mole$

$A{g}^{+}+1e^{-}\to Ag$

1F charge is required for 1 mole of Ag

$H_{2}O\to \frac{1}{2}{O}_2+2H^{+}+2e^{-}$

2F charge deposit $=\frac{1}{2}$ mole

1F charge deposit $=\frac{1}{4}$ mole

$PV=nRT$

$V=\frac{1}{4}\times \frac{0.0821\times 273}{1}$

$V=5.675L$