physical chemistry - the branch of chemistry dealing with the physical properties of chemical substances

force per unit area, pressure, pressure level - the force applied to a unit area of surface; measured in pascals (SI unit) or in dynes (cgs unit); "the compressed gas exerts an increased pressure"

hypertonicity - (of a solution) the extent to which a solution has a higher osmotic pressure than some other

hypotonicity - (of a solution) the extent to which a solution has a lower osmotic pressure than some other