150 g of acetic acid was contaminated with 10.2 g ascorbic acid $\left(\mathrm{C}_6 \mathrm{H}_8 \mathrm{O}_6\right)$ to lower down its freezing point by $\left(x \times 10^{-1}\right)^{\circ} \mathrm{C}$. The value of $x$ is $\_\_\_\_$ . (Nearest integer) [Given $\mathrm{K}_{\mathrm{f}}=3.9 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$; Molar mass of ascorbic acid $=176 \mathrm{~g} \mathrm{~mol}^{-1}$ ]