(A) The same glass vessel used in Example 6-7 is filled with an unknown gas at 772 mmHg and 22.4 °C. The gas-filled vessel weighs 40.4868 g. What is the molar mass of the gas?

(B) A 1.27 g sample of an oxide of nitrogen, believed to be either NO or N₂O, occupies a volume of 1.07 L at 25 °C and 0.982 bar. Which oxide is it?

Example 6-7

Propylene is an important commercial chemical used in the synthesis of other organic chemicals and in production of plastics (polypropylene). A glass vessel weighs 40.1305 g when clean, dry, and evacuated; it weighs 138.2410 g when filled with water at 25.0 °C (density of water = 0.9970 g/mL) and 40.2959 g when filled with propylene gas at 740.3 mmHg and 24.0 °C. What is the molar mass of propylene?