Question

2 moles of $H_2$ burns to form 2 moles of $H_{2}O$. The mass of oxygen used up will be:

• A. 16 g
• B. 32 g
• C. 2 moles
• D. 4 moles

Answer 1

The correct option is B 32 g

The burning of hydroen in presence of oxygen to yield $H_{2}O$ can be represented as

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

Moles of oxygen used $=1$

Hence mass of oxygen used up $=16\times 2=32g$