Question

Concentrated aqueous sulphuric acid is $98\%H_{2}S{O}_4\left(w/v\right)$ and has a density of $1.80{gmL}^{-1}$. Morality of this solution is:

• A. $1M$
• B. $1.8M$
• C. $10M$
• D. $1.5M$

Answer 1

Answer: (C)

$10M$

$98\left(w/v\right)aq.H_{2}S{O}_4$ means $98g$ of $H_{2}S{O}_4$ is present in $100mL$ of water.

Wt. of $H_{2}S{O}_4=98g$

Volume of solution $=100mL$

Molecular wt. of $H_{2}S{O}_4=98g$

As we know that,

$\text{no. of moles}=\frac{\text{wt.}}{\text{mol. wt.}}$

$\therefore \text{No. of moles of}{H}_{2}S{O}_4=\frac{98}{98}=1\text{mol}$

As we know that,

$\text{Molarity}=\frac{\text{no. of moles of solute}}{{\text{Volume of solution}}_{\left(\text{in mL}\right)}}\times 1000$

$\therefore$ Molarity of the given solution $=\frac{1}{100}\times 1000=10M$

Hence the molarity of the solution will be $10M$.

Hence, the correct option is $C$