Cracking the AP Chemistry Exam

Part IV

Content Review for the AP Chemistry Exam

Chapter 7

Big Idea #5: Laws of Thermodynamics and Changes in Matter

FIRST AND SECOND LAWS OF THERMODYNAMICS

The first law of thermodynamics says that the energy of the universe is constant. Energy can be neither created nor destroyed, so while energy can be converted in a chemical process, the total energy remains constant.

The second law of thermodynamics says that if a process is favored in one direction, then it can’t be favored in the reverse direction, and an increase in entropy promotes favored reactions.