The essence of the new approach to the equation of the monolayer state

A new approach to the theory of the equation of state of the adsorption monolayer is elucidated. The approach is based on the excluded surface area. Expressions for the chemical potential are analyzed and the derivation of a master equation, which can be used to obtain equations of state in different approximations, is demonstrated. The constructed hierarchy of approximations includes both the known equations of state (Planck, van der Waals, van Laar, Frumkin) and new, more accurate equations. The new approach consists in the consideration of the three-dimensional aspect related with the orientation of anisometric particles of a monolayer. The influence of the orientational effect on the equation of the monolayer state and phase transitions is discussed.