The molecular weight of the stream is calculated from the weighted average gas molecular weight given by:
The molecular weight of the gas stream of Table 3-1 is calculated in Table 3-2. Column 2 lists the molecular weight of the components from standard reference sources. Column 3 lists the number of moles of each component for 100 moles of feed. This is the same as Column 7 in Table 3-1. Column 4 is derived from Column 2 times Column 3. The molecular weight of the gas is:
The gas specific gravity can be determined from the molecular weight from Equation 3-2 as shown in Table 3-2.