• # question_answer The Van der Waal equation for n moles of a real gas is$\left( p+\frac{a}{{{V}^{2}}} \right)(V-b)=nRT$. Where P is the pressure, V is the volume. T is the absolute temperature. R is the molar gas constant and a and b are Van der Waal constant. The dimensions of a are the same as those of A) PV       B) $P{{V}^{2}}$C) ${{P}^{2}}V$                    D)  $\frac{P}{V}$

From the principle of homogeneity, the dimensions of $\frac{a}{{{V}^{2}}}$must be the same as those of P, i.e., Dimensions of $\frac{a}{{{V}^{2}}}=$ dimensions of P $\therefore$ dimensions of a = dimension of $P{{V}^{2}}.$ Hence, the correction option is [b].