Question

explain why the pure solvent shows a level horizontal curve as solidification occurs, but the curve for the solution slopes downward slightly. ??

Answer 1

Think about it. I don't want to deprive you of the chance to answer this so I will give you some hints. As the liquid cools, the kinetic energy of the molecules decrease and the temperature drops periodically. I assume you know that they way this is done experimentally is to time it and every one minute or so you read the temperature. It shows a steady decline UNTIL the first molecule of solid forms. At that point, what happens? More heat is extracted and another molecule of solid forms. More heat is extracted and a third molecule of solid forms. Can you take it from here?

Answer 2

thanks doctor bob. coulda been a little more straightforward

Answer 3

no