Whether you find a legal PDF or buy the paperback, is an indispensable tool. It turns a "scary" subject into a manageable, logical sequence of ideas. If you want to build a strong foundation in physical chemistry, this is the book to keep on your desk.
Valence Bond (VB) and Molecular Orbital (MO) theories. Looking for the "Quantum Chemistry by RK Prasad PDF"?
Keep a notebook specifically for derivations. Write out the Schrödinger equation solutions multiple times until they become second nature.
Blackbody radiation, photoelectric effect, and the Bohr model.
Are you preparing for a like GATE or CSIR-NET, or just studying for your semester finals ?