Which of the following behaviour is true about the ideal binary liquid solution of liquids ‘A’ and ‘ — Solutions and Colligative Properties Chemistry Question

💡 Solution & Explanation

For an ideal binary solution, $P_{\text{total}} = P_A^\circ X_A + P_B^\circ X_B = P_A^\circ(1 - X_B) + P_B^\circ X_B = P_A^\circ + (P_B^\circ - P_A^\circ)X_B$. Since $P_A^\circ < P_B^\circ$, the term $(P_B^\circ - P_A^\circ)$ is positive. Thus, the plot of $P_{\text{total}}$ vs $X_B$ is a straight line with a positive slope. Therefore, correct answer is B.