${N_1}{V_1} = {N_2}{V_2}$; $25 \times {N_1} = 0.1 \times 35$
${N_1} = \frac{{0.1 \times 35}}{{25}}$ ;
$\therefore M = \frac{{0.1 \times 35}}{{25 \times 2}} = 0.07$.
[આપેલ છે: ${K}_{{f}}=1.86 \,{~K} \,{~kg} \,{~mol}^{-1} ;$ પાણીની ઘનતા $=$ $1.00 \,{~g}\, {~cm}^{-3} ;$ પાણીનું ઠારબિંદુ $\left.=273.15\, {~K}\right]$
(આપેલ : $R =0.083\,L\,bar\,K ^{-1}\,mol ^{-1}$ )