Trying to distinguish between the two Physical Chemistry books written by Raymond Chang? Here is a quick comparison

Physical Chemistry for the Chemical and Biological Sciences, aka Big Blue, weighs in at @1000 pages.  It covers the standard topics in physical chemistry and is suitable for a year-long course. Because the book provides many applications to chemical and biological systems, it has also been used in a one-semester course mainly for premeds and biochemistry majors.

Physical Chemistry for the Biosciences, aka Baby Blue, is @700 pages.  It is specifically designed for a one-semester course geared toward students who are interested in the biological sciences. It is considerably shorter than the first text, due to the omission of topics such as solid and liquid states and statistical thermodynamics, and it has more of a biochemical emphasis.

Both books are carefully designed, student oriented and highly readable with ample references and end-of-chapter problems. And both books have an accompanying Solutions Manual.