Question

How many moles of oxygen gas can be produced during electrolytic decomposition of $180g$ of water?

• A. 2.5 moles
• B. 5 moles
• C. 10 moles
• D. 7 moles

Answer 1

Answer: (B)

5 moles

Water decomposition can be represented as:

$2H_{2}O\to 2H_2+O_2$

$2$ moles (or $2\times 18=36$ g) of water gives one mole of oxygen.

$180$ g water will produce $\frac{180}{36}$ mol of oxygen $=5$ mol of oxygen.

Hence, option $B$ is correct.