Van Laar equation deals with the activity co-efficients in

Answer: Option A

Van Laar equation is an activity based model developed by Van Laar during 1910-1913. Which will be very useful during vapor-liquid equilibrium calculations and the equations for a binary mixture are given as :
$$\begin{array}{rl}& ln{\gamma }_1=\frac{A{X}_2^2}{{\left(\frac{A{X}_1}{B}+X_2\right)}^2}\\ & ln{\gamma }_2=\frac{B{X}_1^2}{{\left(\frac{B{X}_2}{A}+X_1\right)}^2}\end{array}$$