Official course description: Lecture, three hours; discussion, one hour. Enforced requisite: course 14A with grade of C- or better. Enforced corequisite: Mathematics 3A or 31A. Not open to students with credit for course 20A, 20B, or 30A. Phase changes; thermochemistry; first, second, and third laws of thermodynamics; free energy changes; electrochemistry and its role as energy source; chemical kinetics, including catalysis, reaction mechanisms, and enzymes; coordination compounds; general classes and naming of organic molecules; structure, conformations, and relative energies of organic molecules; application of thermodynamics and kinetics to organic and biochemical reactions; use of molecular modeling software to illustrate molecular structures and their relative energies. P/NP or letter grading.