The following is an actual question given on a University of Washington chemistry mid-term:
"Is Неll exothermic (gives off heat) or endothermic (absorbs heat)? Support your answer with a proof."
Most of the students wrote proofs of their beliefs using Boyle’s Law (gas cools off when it expands and heats up when it is compressed) or some variant. One student, however, wrote the following:
First, we need to know how the mass of Неll is changing in time. So, we need to know the rate that souls are moving into Неll and the rate they are leaving. I think that we can safely assume that once a soul gets to Неll, it will not leave. Therefore, no souls are leaving. As for how many souls are entering Неll, let’s look at the different religions that exist in the world today. Some of these religions state that if you are not a member of their religion, you will go to Неll. Since there are more than one of these religions and since people do not belong to more than one religion, we can project that all people and all souls go to Неll. With birth and death rates as they are, we can expect the number of souls in Неll to increase exponentially. Now, we look at the rate of change of the volume in Неll because Boyle’s Law states that in order for the temperature and pressure in Неll to stay the same, the volume of Неll has to expand as souls are added. This gives two possibilities.
1) If Неll is expanding at a slower rate than the rate at which souls enter Неll, then the temperature and pressure in Неll will increase until all Неll breaks loose.
2) Of course, if Неll is expanding at a rate faster than the increase of souls in Неll, then the temperature and pressure will drop until Неll freezes over.
So which is it ? If we accept the postulate given to me by Ms. Therese Banyan during my Freshman year that "It will be a cold night in Неll before I sleep with you," and take into account the fact that I still have not succeeded in having sеxuаl relations with her, then (2) cannot be true, and thus I am sure that Неll is exothermic.
The student got the only A.
