Exam 11: Properties of Gases

A sample of an unknown gas was isolated in a gas containment bulb on a manifold used in this type of work. The volume of the bulb was 1.425 liters. The temperature was 25.40 °C, and the manifold pressure was 583.0 torr. What volume would this gas sample occupy at STP?

A gas sample containing 0.3250 moles of a compound is trapped in a chamber with a volume of 2.460 liters. If the temperature of the gas is 26.8 °C, what is its pressure? Assume the gas exhibits ideal gas behavior.

Dry air contains 78% N₂, 21% O₂, and 1% Ar, by volume. What is the density of air at 900 mmHg and 10°C?

A gas sample has a volume of 12.42 L at STP. How many moles of gas are in the sample?

A sample of oxygen gas was collected by displacement of water in a gas collection apparatus. The total pressure in the collection vessel was 744.2 torr, the temperature was 26.0 °C, and the vessel contained 522 mL of the collected gas. How many moles of oxygen were collected? (At 26.0 °C, the vapor pressure of water is 25.2 torr.)

A gas sample occupies a volume of 1.66 L when the temperature is 150.0 °C and the pressure is 842 torr. How many molecules are in the sample?

A gas evolved during the fermentation of sugar was collected at 22.5°C and 715 mmHg. After purification its volume was found to be 21.0 L. How many moles of the purified gas were collected?

The average speed at which a methane molecule effuses at 28.5 °C is 631 meters per second. The average speed at which krypton gas effuses at this same temperature should therefore be

An open-end mercury manometer was constructed from a U-shaped tube and connected to a gas container. In a particular measurement, the level in the end of the tube connected to the gas container measured 62.0 cm above the U-neck, while the level in the open end (to the atmosphere)was 23.8 cm above the U-neck. The outside air pressure in the laboratory was measured as 772 torr. What is the pressure in the gas container?

An open-end mercury manometer was constructed from a U-shaped tube and connected to a gas container. In a particular measurement, the level in the end of the tube connected to the gas container measured 76.2 cm above the U-neck, while the level in the open end (to the atmosphere)was 23.8 cm above the U-neck. The outside air pressure in the laboratory was measured as 754 torr. What is the pressure in the gas container?

A sample of a gas in a cylindrical chamber with a movable piston occupied a volume of 0.00256 cubic meters when the pressure was 1.20 × 10⁵ Pa and the temperature was 77.8 °C. The volume of the system was readjusted to 1.88 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 gas sample containing 0.3250 moles of a compound is confined in a glass vessel at a temperature of 28.4 °C and a pressure of 846 torr. What is the volume of the vessel?

A certain gas is applying a force of 2.5 N to the surface of a piston. This surface on the piston has an area of 0.75 m². What is the pressure being applied to the surface of the piston?Hint: 1 Pa = 1 N/m^2.

A sample of methane gas (CH₄)was collected by displacement of water in a gas collection flask. The total pressure in the collection flask was measured as 758.2 torr, the temperature was 25.0 °C, and the measured volume of gas in the flask was 526.0 mL. How many grams should the methane weigh? (At 25.0 °C, the vapor pressure of water is 23.8 torr.)

A chemical reaction, A(s) $\rarr$ B(s)+ C(g), occurs when substance A is strongly heated. The molecular mass of the gaseous product was to be determined from the following experimental data: Mass of A before reaction starts: 5.467 g Mass of A after reaction finishes: 0 g Mass of residue (B)after cooling and weighing when no more gas was evolved: 4.762 g When all of the gas C evolved was collected and stored in an 875.0 mL glass vessel at 30.50 °C, the gas exerted a pressure of 346.0 torr.From this data, determine the apparent molecular mass of C assuming it behaves as an ideal gas.

A sample of hydrogen gas is placed in a solid steel chamber (rigid walls)with a volume of 4.25 L. The sample starts at a temperature of 25.0°C and pressure of 1.00 atm. What would be the final pressure if gas sample is heated to a new temperature of 100°C?

A sample of a gas occupies a volume of 1.462 liters at 30.00°C and 1.250 atm. It was placed in a different vessel in which the pressure was measured as 722.5 torr when the temperature was 25.20 °C. What is the volume of this new vessel?

A gas sample occupies a volume of 18.86 liters when the temperature is 35.2 ^°C and the pressure is 735.5 torr. How many moles of gas are in the sample?

According to the kinetic theory of gases, the average kinetic energy of the gas particles in a gas sample is directly proportional to the

What are the values for standard temperature and pressure (STP)in units of °C and mmHg?