(આપેલ, $K_f = 5\,K\, kg\,mol^{-1},$ બેન્ઝોઇક એસિડનું મોલર દળ $= 122\,g\,mol^{-1}$ )
\(1 - \alpha \) \(\frac{\alpha }{2}\)
\(1 - 0.8\) \(\frac{{0.8}}{2}\)
\(i\, = 1 - 0.8\, + \,\frac{{0.8}}{2}\, = \,0.6\)
\(\Delta {T_f}\, = \,{K_f}\, \times \,\,i\,\, \times \,\,m\) \( = \,5\,\, \times \,0.6\,\, \times \,\frac{X}{{122}}\, \times \,\frac{{1000}}{{30}}\, = \,2\) (Since \(\Delta {T_f}\, = \,2\) )
\(\therefore \,X\, = \,2.44\,g\)