Question

Calculate the molality of $1$ L solution of $93$% $H_{2}S{O}_4$ (weight/volume). The density of the solution is $1.84$ g.

(If the answer is x, then find [x] )

Answer 1

$Density=1.84g{L}^{-1}$
Mass of $100$ mL solution $=100\times 1.84=184g$
Mass of $H_{2}S{O}_4$ in $100$ mL solution $=93g$
Mass of water in $100$ mL solution $=184-93=91g$
The molality of the solution is the number of moles of solute present in $1$ kg of solvent.
Molality $=\frac{93}{98}\times \frac{1}{91}\times 1000=10.428$
Thus, the molality of $1$ L solution of $93$% $H_{2}S{O}_4$ (weight/volume) solution having density $1.84$ g/ml is $10.428$ m.