Which one of the following graphs accurately represents the plot of partial pressure of CS ₂ vs its mole fraction in a mixture of acetone and CS ₂ at constant temperature?

Step-by-step solution

The partial pressure of a component in a binary mixture follows Raoult's law for ideal solutions: P_ i = x_i P°_i , which is linear. However, the acetone-CS₂ system exhibits positive deviation from ideality due to different molecular interactions. When acetone and CS₂ mix, the hydrogen bonding between acetone molecules is disrupted, and the weaker interactions between unlike molecules allow molecules to escape more easily into the vapor phase. This results in partial pressures higher than predicted by Raoult's law,