Question 1

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.

Accepted Answer

A) 13.87 g mol -1 
B) 30.40 g mol -1 
C) 104.0 g mol -1 
D) 106.7 g mol -1 
E) 110.0 g mol -1

Question 2

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?

Accepted Answer

A) 462.6 torr 
B) 576.9 torr 
C) 715.5 torr 
D) 988.6 torr 
E) 1233 torr

Question 3

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?

Accepted Answer

The answer of The density of a gas sample was...

Question 4

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

Accepted Answer

A) True 
 B)False

Question 5

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?

Accepted Answer

A) 41.5 °C 
B) 41.9 °C 
C) 189.8 °C 
D) 194.7 °C 
E) 288.6 °C

Question 6

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.

Accepted Answer

The answer of A gaseous mixture is 20.00% argon, 25.00%...

Question 7

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?

Accepted Answer

A) 0.400 atm 
B) 0.741 atm 
C) 3.13 atm 
D) 6.49 atm 
E) 16.5 atm

Question 8

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?

Accepted Answer

The answer of In many science fiction movies, characters that...

Question 9

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?

Accepted Answer

A) 5.71 liters 
B) 11.0 liters 
C) 11.2 liters 
D) 22.4 liters 
E) 44.0 liters

Question 10

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?

Accepted Answer

A) -32.6 °C 
B) -10.6 °C 
C) +11.0 °C 
D) +37.0 °C 
E) +41.7 °C

Question 11

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.}

Accepted Answer

The answer of An open-end manometer constructed from a U-shaped...

Question 12

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?

Accepted Answer

A) 0.150 
B) 0.400 
C) 0.660 
D) 0.870 
E) 0.930

Question 13

Deviations from ideal gas behavior are greatest at ________.

Accepted Answer

The answer of Deviations from ideal gas behavior are greatest...

Question 14

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.

Accepted Answer

The answer of A piece of zinc is allowed to...

Question 15

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?

Accepted Answer

A) 0.70 
B) 0.24 
C) 0.46 
D) 0.66 
E) 0.34

Question 16

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

Accepted Answer

A) He 
B) SF6 
C) CO2 
D) CH4 
E) CFH3

Question 17

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?

Accepted Answer

A) 489.9 torr 
B) 569.4 torr 
C) 621.5 torr 
D) 929.4 torr 
E) 1179 torr

Question 18

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

Accepted Answer

The answer of Calculate the density, in g/L, of SF₆...

Question 19

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?

Accepted Answer

A) 1.90 × 1022 
B) 2.82 × 1022 
C) 4.71 × 1022 
D) 9.10 × 1021 
E) 9.10 × 1022

Question 20

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

Accepted Answer

The answer of Why are canisters of spray paint and...

Exam 11: Properties of Gases

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 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?

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?

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 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"?

Exam 11: Properties of Gases

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 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?

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?

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 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"?

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?

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?

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