Equilibria in a Polymerizing Gas

Hirschfelder, C. F. Curtiss, and R. B. Bird, Molecular Theory of Gases and 

When this equation is compared with equation (20), it is apparent that 

In principle, therefore, knowledge of 5, C, D,permits derivation of X2, Xa, X4,. It should be noted that WooUey s treatment relates to clusters, i.e. groups of molecules in close proximity to each other, which may result from either random motions or loose binding of monomer molecules to form dimers and higher polymers. Hirschfelder, McClure, and Weeks gave a treatment that is specific for a gas dimerizing to a small extent  

In the case of a gas that dimerizes and forms one higher polymer (again to a small extent only), the following equation may be derived  

In the ensuing account of modem p, K, T methods we shall emphasize the use of the virial equation of state in interpreting measured quantities. For this purpose we shall utilize a version of equation (15) that explicitly cites the volume V occupied by an amount n of gas at pressure p and temperature T, namely 

---