Question

The total volume of dry gaseous products at $STP$ , when 3 moles of electrons are transferred from anode to cathode in the electrolysis of water is:

(Volume of gas a STP = 22.4 L)

• A. $67.2 \, L$
• B. $50.4 \, L$
• C. $44.8 \, L$
• D. $56.0 \, L$

Answer 1

Answer: (B)

$3O\overset{\Theta}{H} \rightarrow \frac{3}{4}O_{2}+\frac{3}{2}H_{2}O+3e^{-}\left(\right.Anode\left.\right)$

$3H^{+}+3e^{-} \rightarrow \frac{3}{2}H_{2}\left(\right.Cathode\left.\right)$

$\frac{3}{4}$ mole $O_{2}$ (Anode) $+\frac{3}{2}$ mole $H_{2}$ (cathode)

mole of gas $=\frac{3}{4}+\frac{3}{2}=\frac{9}{4}$

mole of gas $=\frac{9}{4}\times 22.4$

$=50.4 \, L$