Question

Molarity of $H_{2}S{O}_4$ is 18 M. Its density is 1.8 g/ml, hence molality is :

• A. $18$
• B. $100$
• C. $36$
• D. $500$

Answer 1

The correct option is D $500$

Moles of $H_{2}S{O}_4$ present per litre of solution is 18

Weight of 1 litre of solution $=1000\times 1.8=1800gm$

Weight of $H_{2}S{O}_4=18\times 98=1764gm$

Weight of solvent$=1800-1764=36gm$

Molality of $H_{2}S{O}_4=\frac{18}{36}\times 1000=500m$