If the vapor pressure of a solution is higher than predicted by Raoult's law, then the temperature of the solvents when put into solution will: A. increase due to the energy absorbed by the breaking of bonds. B. increase due to the energy released by the formation of bonds. C. decrease due to the energy absorbed by the breaking of bonds. D. decrease due to the energy released by the formation of bonds. If its higher then predicted that means bonds were broken and we now have weaker bonds then before, and (delta)H would be positive because we are breaking bonds. This eliminates choice B and D since bonds are broken not formed. Now I had to find out what happens to the temperate of the solvents. I reasoned that they would absorb more energy because (delta)H = positive and since energy is proportional to temperature I thought that their temp would increase. I choose A. The correct answer listed in C, the temperate of the solvents will decrease. This is the solution given. Solution Since Ptotal is higher than predicted by Raoult's Law, we must consider the second graph in Figure 1, which illustrates the case where (delta)Hs > 0. Since the mixture is an endothermic reaction, the result will be a decrease in the temperature of the solution. The answer says the result will be a decrease in the temp of the solution... Is this the same as a decrease in the temp of the solvents? I still dont really understand why the temp would decrease and not increase if delta h is positive. I could see how maybe the energy is coming from the solution to break the bonds but the question is asking about the temperature of the solvents. Would these be the same or diff then the solution? Any help would be awesome! Thanks.