Question

Four moles of electrons were transferred from anode to cathode in an experiment on electrolysis of water. The total volume of the two gases (dry and at STP) produced will be approximately (in litres)

• A. 22.4
• B. 44.8
• C. 67.2
• D. 89.4

Answer 1

Answer: (C)

67.2

Answer 2

At Cathode :$\text{2}\text{H}_{2}\text{O + 2e- }\overset{\quad\quad}{\rightarrow}H_{2}\text{ + 2O}\text{H}^{-}\text{ }\rbrack\text{ × 2}$At Anode :$\text{2}\text{H}_{2}\text{O }\overset{\rightarrow}{\quad\quad}O_{2}\text{ + 4}\text{H}^{+}\text{ + 4}\text{e}^{-}\$H2 = 2 mole

O2 = 1 mole

Total volume = 3 × 22.4 = 67.2 L.