Question asks about a mix between two volatile components, where the vapor pressure of the solution is lower than pure B's VP, but higher than A's vp. What can be concluded about relative IMF's?

Why is the answer that the intermolecular forces between particles A and B are weaker than those between particles of A and those between particles of B? Is it because the solution's vapor pressure is higher than pure A's vapor pressure, thus the solution has weaker intermolecualr forces than of just pure A?

  • The main reason I am confused, is that I recognize that the A-B interactions are stronger than B-B interactions, but that A-B interactions are weaker than A-A interactions. It thus doesn't make sense to me to blanket say that the forces between A and B are weaker than those between A and A and those between B and B. Brandon commented over 3 years ago
  • Since higher vapor pressures corresponds to more gas in equilibrium, the intermolecular forces are therefore primarily weaker for higher vapor pressures. Nika commented over 3 years ago