Question

Calculate the molality of $1$ litre solution of $98\%$ $H_{2}S{O}_4$ (weight/volume). The density of the solution is $1.88g/mL$.

Answer 1

$98\%\left(w/V\right)$ $H_{2}S{O}_4$ means $98g$ $H_{2}S{O}_4$ in $100mL$ of the solution.
Again, density of the solution is $1.88g/mL$
So mass of $1000mL$ solution = $1880g$
Mass of $H_{2}S{O}_4$ in $1000mL$ solution = $980g$
So mass of the solvent = $1880-980=900g=0.90kg$
Hence molality = $\frac{\frac{980}{98}}{0.90}=11.11m$