\(\Delta {T_f}\, = \,\,i\,{K_f}m\)
\(10\, = \,1\, \times \,1.86\,\frac{{\frac{{62}}{{62}}}}{{\frac{{250\, - \,x}}{{1000}}}}\)
\(x\, = \,64\,gm\)
[આપેલ છે: ${K}_{{f}}=1.86 \,{~K} \,{~kg} \,{~mol}^{-1} ;$ પાણીની ઘનતા $=$ $1.00 \,{~g}\, {~cm}^{-3} ;$ પાણીનું ઠારબિંદુ $\left.=273.15\, {~K}\right]$
(આણ્વિય દળ $\left.\mathrm{H}_{2} \mathrm{SO}_{4}=98 \;\mathrm{g} / \mathrm{mol}\right)$