3. Humid air is less dense than dry air at the same temperature and pressure. Ex

Question

3. Humid air is less dense than dry air at the same temperature and pressure. Explain. 4. What if a small amount of air leaked back into the flask through the tightened screw clamp as the flask assembly was cooling? Would your calculated value for the molar mass of air be too high, too low, or would there be no effect? Explain. C6 5. You perform this same experiment on the surface of Venus using Venusian "air". The barometric pressure is 68,800 mm of Hg, and the volume of the flask assembly is 125.0 mL. The flask assembly containing Venusian air weighs 178.392 g at 450.0 °C and decreases to 177.155 g at 575.0 °C. What is the apparent molar mass of Venusian air? Show all your work. (You may use the back of this page if need be).

Explanation / Answer

3.

Moist air is less dense than its equivalent ( at same pressure and temperature) dry air. It is because of the less molecular weight of moist air.
Water vapor (Molecular Mass = 10g) is a relatively light gas when compared to O2 and N2 molecules. Thus, as the amount of water vapor increases, the amount of Oxygen and Nitrogen decrease per unit volume and thus density decreases because mass is decreasing. (density = mass/volume, for constant volume)

Hence, moist air is less dense than dry air under the same temperature, pressure and volume.

For rest of the question, details about experiment are missing.

Related Questions

Navigate

• Browse (All)
• Browse 3
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.