(a) What does the dotted plot signify?

(b) Which is true: $\mathbf{T}_{1}>\mathbf{T}_{2}$ or $\mathbf{T}_{1}<\mathbf{T}_{2}$ ?

Solution:

(a) The dotted plot is perpendicular to the x-axis, indicating that $n R[P \vee / T=n R]$ is unaffected by $P$. As a result, it represents optimal gas behaviour.

(b) The graph at $T_{1}$ is closer to ideal behaviour (since it is closer to the dotted line), hence $T_{1}>$ $\mathrm{T}_{2}$ (higher the temperature, ideal behaviour is the higher)