MCAT Physics Question 43: Answer and Explanation

Home > MCAT Test > MCAT physics practice tests

Test Information

Question: 43

13. Substances A and B have the same freezing and boiling points. If solid samples of both substances are heated in the exact same way, substance A boils before substance B. Which of the following would NOT explain this phenomenon?

  • A. Substance B has a higher specific heat.
  • B. Substance B has a higher heat of vaporization.
  • C. Substance B has a higher heat of fusion.
  • D. Substance B has a higher internal energy.

Correct Answer: D

Explanation:

Saying that substance B has a higher internal energy cannot explain the phenomenon because the internal energy is irrelevant; the heat involved in the process is related only to the specific heat, the heat of fusion, and the heat of vaporization. All of the other choices could explain the phenomenon. The heat required to melt the solid is determined by the heat of fusion, choice (C). The heat required to bring the liquid to its boiling point is determined by the specific heat, choice (A). The heat required to boil the liquid is determined by the heat of vaporization, choice (B).

Previous       Next