## Appendix C. Detailed Equations for Flammability Diagrams^{1}

### Equations Useful for Gas Mixtures

In this appendix we derive several equations that are useful for working with flammability diagrams. Section 6-5 provides introductory material on the flammability diagram. In this section we derive equations proving that:

**1.** If two gas mixtures R and S are combined, the resulting mixture composition lies on a line connecting the points R and S on the flammability diagram. The location of the final mixture on the straight line depends on the relative moles of the mixtures combined. If mixture S has more moles, the final mixture point will lie closer to point S. This is identical to the lever rule used for phase diagrams.

**2.** If a mixture R is continuously ...