Chemistry - Concentration Terms Question with Solution | TestHub

Molality ($m$) = 25 means 25 moles of solute are dissolved in 1000 g of water.

Mass of solute = $moles\times molarmass=25\times \frac{40}{3}g=\frac{1000}{3}g$.

Total mass of solution = $watermass+solutemass=1000+\frac{1000}{3}=\frac{4000}{3}g$.

Volume of solution = $\frac{TotalMass}{Density}=\frac{4000/3}{3.2}=\frac{1250}{3}mL=\frac{1.25}{3}L$.

Molarity ($M$) = $\frac{Molesofsolute}{Volumeofsolution(L)}=\frac{25}{1.25/3}=60M$ (Option D).