physical chemistry

Branch of chemistry concerned with examining the relationships between the chemical compositions of substances and the physical properties that they display. Most chemical reactions exhibit some physical phenomenon (change of state, temperature, pressure, or volume, or the use or production of electricity), and the measurement and study of such phenomena has led to many chemical theories and laws.

Physical chemistry includes the fields of thermodynamics, electrochemistry, quantum chemistry, and kinetics. Many of the analytical techniques used in other chemical disciplines have their roots in physical chemistry.