Question

Concentrated aqueous sulphuric acid is $98 \% H _{2} SO _{4}$ by mass and has a density of $1.80 g mL ^{-1}$. Volume of acid required to make one litre of $0.1 M H _{2} SO _{4}$ solution is

• A. 11.10 mL
• B. 16.65 mL
• C. 22.20 mL
• D. 5.55 mL

Answer 1

Answer: (D)

$H _{2} SO _{4}$ is $98 \%$ by weight

Weight of $H _{2} SO _{4}=98\, g$

Weight of solution $=100 \,g$

Volume of solution $=\frac{\text { Mass }}{\text { Density }}=\frac{100}{1.80} mL$

$=55.55 mL =0.0555 L$

Molarity of solution $=\frac{98}{98 \times 0.0555} \approx 18.02 M$

Let $V mL$ of $H _{2} SO _{4}$ be used to prepare one litre of 0.1 $M H _{2} SO _{4}$

$V \times 18.02=1000 \times 0.1$

$V =\frac{1000 \times 0.1}{18.02}=5.55 \,mL$