1.
When 20 g20\,\text{g} of naphthoic acid (C11H8O2\text{C}_{11}\text{H}_8\text{O}_2) is dissolved in 50 g50\,\text{g} of benzene (Kf=1.72 K⋅kg⋅mol−1K_f = 1.72\,\text{K·kg·mol}^{-1}), a freezing point depression of 2 K2\,\text{K} is observed. The Van't Hoff factor (ii) is