Molarity of a solution of density 1.5 g/ml is 1 M. Molality of the same solution under similar conditions will be (Molar mass of solute - 150 g)

Molarity of the solution = 1M

Number of moles of solute = 1

Volume of the solution = 1000 ml

Density of the solution = 1.5 g/ml

Weight of the solution = V x d = 1500 g

Weight of solute = ${\mathrm{W}}_{\mathrm{solution}}-{\mathrm{W}}_{\mathrm{solute}}$

                          = (1500 - 150) g

                         = 1350 g

molality (m) = ${\mathrm{n}}_{\mathrm{solute}}\times \frac{1000}{{\mathrm{W}}_{\mathrm{solvent}}}$

                   =$1\times \frac{1000}{1350}=0.74 \mathrm{m}$