Solute A associates in water. When 0 . 7g of solute A is dissolved...

Depression in freezing point,${\Delta T}_{f} = {iK}_{f} \times m$

$2 . 0 = ix1 . 86 \times \dfrac{7 \times 1000}{93 \times 42}$

$2 . 0 = i\left[3 . 33\right]$

$i = 0 . 6$

$i = 1 + \left[\dfrac{1}{n} - 1\right]\beta$

$0 . 6 = 1 + \left[\dfrac{1}{2} - 1\right]\beta$

$\beta = 0 . 8$

$$

Hence, the percentage association of solute A in water is 80.