2.19. K-values from the PR and SRK equations. Use a process simulation program to estimate the K-values, using the P-R and S-R-K equations of state, of an equimolar mixture of the two butane isomers and the four butene isomers at 220F and 276.5 psia. Compare these values with the following experimental results [J. Chem. Eng. Data, 7, 331 (1962)]