Question

$4$ g of hydrogen are ignited with $4$ g of oxygen. The weight of water formed is :

• A. $0.5$ g
• B. $3.5$ g
• C. $4.5$ g
• D. $2.5$ g

Answer 1

The correct option is C $4.5$ g

The balanced chemical reaction is $2H_2+O_2\to 2H_{2}O$.

$4$ g of hydrogen will react with $\frac{4\times 32}{4}=32$ g of oxygen.

However, only $4$ g of oxygen are present.

Thus, oxygen is the limiting reagent.

$4$ g of oxygen will give $\frac{4\times 36}{32}=4.5$ g of water.