A 0 . 5 percent solution of potassium chloride was found to freeze...

$KCl \to {K}^{+} + {Cl}^{-}$

$1 - -$

$1 - \alpha\alpha\alpha$

$i = 1 - \alpha + 2\alpha = 1 + \alpha$

$∆ {T}_{f} = i{K}_{f} \cdot m$

$0 . 24 = \left(1 + \alpha\right)1 . 80 \times \dfrac{0 . 5}{74 . 6} \times \dfrac{1000}{99 . 5}$

$\alpha = 0 . 98\alpha$