Exam 11: Properties of Gases

A student doing a laboratory study on determination of molecular mass of gases obtained the following data for one of his unknowns: 6.155 grams of the gas occupied a volume of 1484 mL when its temperature was 27.3 °C and its pressure was 747.2 torr. Calculate the molecular mass of the gas, assuming ideal gas behavior.

A cylinder fitted with a movable piston and filled with a gas has a volume of 188.5 mL at 26.7 °C when the applied pressure is 755.2 torr. The temperature of the oil bath surrounding the cylinder was increased to 165.2 °C and the load on the piston was changed. Careful measurement now gave a value of 210.5 mL for the volume. What is the final pressure in the system?

The density of a gas sample was found to be 3.51 g/L. If the pressure of the sample was changed from 1.00 atm to 3.00 atm under constant temperature, what would be the new density of the sample?

The density of a pure gaseous substance is inversely proportional to its absolute temperature.

A sample of a gas in a cylindrical chamber with a movable piston occupied a volume of 1.40 liters when the pressure was 768 torr and the temperature was 26.9 °C. The volume of the system was readjusted to 2.16 liters by changing the temperature while the load on the piston was kept constant to keep the pressure in the system constant. What is the temperature in the system at this point?

A gaseous mixture is 20.00% argon, 25.00% nitrogen, 30.00% methane and 25.00% ethylene, C₂H₄ by weight. Calculate the percent, by volume, of methane in the mixture.Hint: Consider the difference between mass and moles.

What is the total pressure exerted by a gaseous mixture that consists of 8.00 g of methane and 12.00 g of ethane, C₂H₆, in a 3.50 L container maintained at 35.20 °C?

In many science fiction movies, characters that are suddenly pulled into outer space experience phenomena such as their heads exploding or their eyes bulging. Provide a reasonable explanation based on the properties of gases for why movies speculate that this could happen, even though it is exaggerated?

What volume would 11.2 g of a gaseous compound occupy at STP if its molecular weight is 44.0 g/mole and it behaves as an ideal gas?

A sample of a gas occupies a volume of 1.462 liters at STP. It was placed in a different vessel with a volume of 1.601 liters, in which the pressure was measured as 722.0 torr. What is its temperature in this new vessel?

An open-end manometer constructed from a U-shaped tube was operated using an oil that has a density of 1.164 g mL⁻¹. In a particular measurement, the level in the end connected to the gas vessel, on which the experiment was being conducted, measured 82.8 cm above the U-neck, while the level in the open end was 17.2 cm above the U-neck. The outside air pressure in the laboratory was measured as 764 torr. What is the pressure in the gas vessel?Hint: The density of mercury is 13.533 g mL^{−1 at room temperature.}

What is the mole fraction of hydrogen in a gaseous mixture that consists of 8.00 g of hydrogen and 12.00 g of neon in a 3.50-liter container maintained at 35.20 °C?

Deviations from ideal gas behavior are greatest at ________.

A piece of zinc is allowed to react with an excess quantity of sulfuric acid and the hydrogen gas produced is collected in a gas buret by displacement of water. Neglecting the effect of the vapor pressure of water on the system, calculate how many mg of zinc would generate 92.0 mL of the gas at a temperature of 25.0 ^°C and a pressure of 1.00 atm. ________Hint: Find the moles of gas first.

A sealed glass container contains partial pressures of 0.24 atm O₂ gas and 0.46 atm H₂ gas. What is the mole fraction of H₂ in the glass container?

Which of the following gases will have the greatest density at the same specified temperature and pressure?

A sample of a gas occupies a volume of 185.5 mL at STP. What pressure would it exert if it was transferred to a gas bulb with a volume of 255.5 mL in which the temperature is maintained at 34.5 °C?

Calculate the density, in g/L, of SF₆ gas at 27.0°C and 1.00 atm pressure.

A gas sample occupies a volume of 1.446 L when the temperature is 185.0 °C and the pressure is 624 torr. How many molecules are in the sample?

Why are canisters of spray paint and hairspray labeled, "Keep away from heat sources"?