Question 1

0.7515 moles of nitrogen gas and 0.1135 moles of methane gas are placed in a 171.6 ml container at 20.8 °C.What is the partial pressure (atm)of methane gas?

Accepted Answer

A) 1.14 
B) 0.473 
C) 16.0 
D) 106 
E) 226 
A) 1.14 
B) 0.473 
C) 16.0 
D) 106 
E) 226

Question 2

The molecular weight of a gas is ________ g/mol if 6.7 g of the gas occupies 6.3 L at STP.

Accepted Answer

A) 24 
B) 3.6 × 103 
C) 27 
D) 3.0 × 102 
E) 1.8 × 10-2 
A) 24 
B) 3.6 × 103 
C) 27 
D) 3.0 × 102 
E) 1.8 × 10-2

Question 3

Which of the following statements about gases is false?

Accepted Answer

A) Gases are highly compressible. 
B) Distances between molecules of gas are very large compared to bond distances within molecules. 
C) Non-reacting gas mixtures are homogeneous. 
D) Gases expand spontaneously to fill the container they are placed in. 
E) All gases are colorless and odorless at room temperature. 
A) Gases are highly compressible. 
B) Distances between molecules of gas are very large compared to bond distances within molecules. 
C) Non-reacting gas mixtures are homogeneous. 
D) Gases expand spontaneously to fill the container they are placed in. 
E) All gases are colorless and odorless at room temperature.

Question 4

What volume (mL)of fluorine gas is required to react with 1.28 g of calcium bromide to form calcium fluoride and bromine gas at STP?

Accepted Answer

A) 28.7 
B) 144 
C) 31.3 
D) 157 
E) 13.1 
A) 28.7 
B) 144 
C) 31.3 
D) 157 
E) 13.1

Question 5

A sample of gas (1.9 mol)is in a flask at 21 °C and 697 mm Hg.The flask is opened and more gas is added to the flask. The new pressure is 841 mm Hg and the temperature is now 26 °C.There are now ________ mol of gas in the flask.

Accepted Answer

A) 1.6 
B) 2.3 
C) 2.9 
D) 3.5 
E) 0.28 
A) 1.6 
B) 2.3 
C) 2.9 
D) 3.5 
E) 0.28

Question 6

A sample of a gas originally at 25 °C and 1.00 atm pressure in a 2.5 L container is subject to a pressure of 0.85 atm and a temperature of 15 °C.The final volume of the gas is ________ L.

Accepted Answer

A) 3.0 
B) 2.8 
C) 2.6 
D) 2.1 
E) 0.38 
A) 3.0 
B) 2.8 
C) 2.6 
D) 2.1 
E) 0.38

Question 7

What is the density of chlorine gas (g/L)at 1.01 atm and 54.1 °C?

Accepted Answer

A) 2.67 
B) 0.0376 
C) 0.375 
D) 0.228 
E) 1.33 
A) 2.67 
B) 0.0376 
C) 0.375 
D) 0.228 
E) 1.33

Question 8

How many liters of CO2 are formed during the combustion of 120.0 grams of ethane at STP in the open atmosphere?

Accepted Answer

Question 9

In ideal gas equation calculations,expressing pressure in Pascals (Pa),necessitates the use of the gas constant,R,equal to ________.

Accepted Answer

A) 0.08206 atm L mol-1K-1 
B) 8.314   -Pa/mol-K 
C) 62.36 L torr mol-1K-1 
D) 1.987 cal mol-1K-1 
E) none of the above 
A) 0.08206 atm L mol-1K-1 
B) 8.314   -Pa/mol-K 
C) 62.36 L torr mol-1K-1 
D) 1.987 cal mol-1K-1 
E) none of the above

Question 10

The kinetic-molecular theory predicts that pressure rises as the temperature of a gas increases because ________.

Accepted Answer

A) the average kinetic energy of the gas molecules decreases 
B) the gas molecules collide more frequently with the wall 
C) the gas molecules collide less frequently with the wall 
D) the gas molecules collide more energetically with the wall 
E) B and D 
A) the average kinetic energy of the gas molecules decreases 
B) the gas molecules collide more frequently with the wall 
C) the gas molecules collide less frequently with the wall 
D) the gas molecules collide more energetically with the wall 
E) B and D

Question 11

Real gases do not behave ideally at ________.

Accepted Answer

A) high pressure and low temperature 
B) low pressure and high temperature 
C) high pressure and high temperature 
D) low pressure and low temperature 
E) high pressure only 
A) high pressure and low temperature 
B) low pressure and high temperature 
C) high pressure and high temperature 
D) low pressure and low temperature 
E) high pressure only

Question 12

A tank containing both HF and HBr gases developed a leak.The ratio of the rate of effusion of HF to the rate of effusion of HBr is ________.

Accepted Answer

A) 4.04 
B) 0.247 
C) 2.01 
D) 0.497 
E) 16.3 
A) 4.04 
B) 0.247 
C) 2.01 
D) 0.497 
E) 16.3

Question 13

According to the kinetic-molecular theory,molecules of different gases at the same temperature always have the same average kinetic energy.

Accepted Answer

A) True 
 B)False

Question 14

The van der Waals equation for real gases recognizes that ________.

Accepted Answer

A) gas particles have non-zero volumes and interact with each other 
B) molar volumes of gases of different types are different 
C) the non-zero volumes of gas particles effectively decrease the amount of "empty space" between them 
D) the molecular attractions between particles of gas decreases the pressure exerted by the gas 
E) all of the above statements are true 
A) gas particles have non-zero volumes and interact with each other 
B) molar volumes of gases of different types are different 
C) the non-zero volumes of gas particles effectively decrease the amount of "empty space" between them 
D) the molecular attractions between particles of gas decreases the pressure exerted by the gas 
E) all of the above statements are true

Question 15

A sample of He gas (2.35 mol)occupies 57.9 L at 300.0 K and 1.00 atm.The volume of this sample is ________ L at 469 K and 1.00 atm.

Accepted Answer

A) 0.709 
B) 41.1 
C) 90.5 
D) 1.41 
E) 57.9 
A) 0.709 
B) 41.1 
C) 90.5 
D) 1.41 
E) 57.9

Question 16

A gas at a pressure of 325 torr exerts a force of ________ N on an area of 5.5 m2.

Accepted Answer

A) 1.8 × 103 
B) 59 
C) 2.4 × 105 
D) 0.018 
E) 2.4 
A) 1.8 × 103 
B) 59 
C) 2.4 × 105 
D) 0.018 
E) 2.4

Question 17

How much faster does 79Br2 effuse than 81Br2?

Accepted Answer

A) 0.975 times as fast 
B) 1.025 times as fast 
C) 1.013 times as fast 
D) 0.988 times as fast 
E) Cannot be determined 
A) 0.975 times as fast 
B) 1.025 times as fast 
C) 1.013 times as fast 
D) 0.988 times as fast 
E) Cannot be determined

Question 18

If 3.21 mol of a gas occupies 56.2 L at 44 °C and 793 torr,4.73 mol of this gas occupies ________ L under these conditions.

Accepted Answer

A) 14.7 
B) 61.7 
C) 30.9 
D) 82.8 
E) 478 
A) 14.7 
B) 61.7 
C) 30.9 
D) 82.8 
E) 478

Question 19

The molar volume of a gas at STP is ________ L.

Accepted Answer

A) 0.08206 
B) 62.36 
C) 1.00 
D) 22.4 
E) 14.7 
A) 0.08206 
B) 62.36 
C) 1.00 
D) 22.4 
E) 14.7

Question 20

An ideal gas differs from a real gas in that the molecules of an ideal gas ________.

Accepted Answer

A) have no attraction for one another 
B) have appreciable molecular volumes 
C) have a molecular weight of zero 
D) have no kinetic energy 
E) have an average molecular mass 
A) have no attraction for one another 
B) have appreciable molecular volumes 
C) have a molecular weight of zero 
D) have no kinetic energy 
E) have an average molecular mass

Exam 10: Gases

0.7515 moles of nitrogen gas and 0.1135 moles of methane gas are placed in a 171.6 ml container at 20.8 °C.What is the partial pressure (atm)of methane gas?

The molecular weight of a gas is ________ g/mol if 6.7 g of the gas occupies 6.3 L at STP.

Which of the following statements about gases is false?

What volume (mL)of fluorine gas is required to react with 1.28 g of calcium bromide to form calcium fluoride and bromine gas at STP?

A sample of gas (1.9 mol)is in a flask at 21 °C and 697 mm Hg.The flask is opened and more gas is added to the flask. The new pressure is 841 mm Hg and the temperature is now 26 °C.There are now ________ mol of gas in the flask.

A sample of a gas originally at 25 °C and 1.00 atm pressure in a 2.5 L container is subject to a pressure of 0.85 atm and a temperature of 15 °C.The final volume of the gas is ________ L.

What is the density of chlorine gas (g/L)at 1.01 atm and 54.1 °C?

How many liters of CO2 are formed during the combustion of 120.0 grams of ethane at STP in the open atmosphere?

In ideal gas equation calculations,expressing pressure in Pascals (Pa),necessitates the use of the gas constant,R,equal to ________.

The kinetic-molecular theory predicts that pressure rises as the temperature of a gas increases because ________.

Real gases do not behave ideally at ________.

A tank containing both HF and HBr gases developed a leak.The ratio of the rate of effusion of HF to the rate of effusion of HBr is ________.

According to the kinetic-molecular theory,molecules of different gases at the same temperature always have the same average kinetic energy.

The van der Waals equation for real gases recognizes that ________.

A sample of He gas (2.35 mol)occupies 57.9 L at 300.0 K and 1.00 atm.The volume of this sample is ________ L at 469 K and 1.00 atm.

A gas at a pressure of 325 torr exerts a force of ________ N on an area of 5.5 m2.

How much faster does 79Br2 effuse than 81Br2?

If 3.21 mol of a gas occupies 56.2 L at 44 °C and 793 torr,4.73 mol of this gas occupies ________ L under these conditions.

The molar volume of a gas at STP is ________ L.

An ideal gas differs from a real gas in that the molecules of an ideal gas ________.

Introduction: Matter, energy, and Measurement

Atoms, molecules, and Ions

Chemical Reactions and Reaction Stoichiometry

Reactions in Aqueous Solution

Thermochemistry

Electronic Structure of Atoms

Periodic Properties of the Elements

Basic Concepts of Chemical Bonding

Molecular Geometry and Bonding Theories

Liquids and Intermolecular Forces

Solids and Modern Materials

Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acid-Base Equilibria

Additional Aspects of Aqueous Equilibria

Chemistry of the Environment

Chemical Thermodynamics

Electrochemistry

Nuclear Chemistry

Chemistry of the Nonmetals

Transition Metals and Coordination Chemistry

The Chemistry of Life: Organic and Biological Chemistry

Filters

How many liters of CO₂ are formed during the combustion of 120.0 grams of ethane at STP in the open atmosphere?

A gas at a pressure of 325 torr exerts a force of ________ N on an area of 5.5 m².

How much faster does ⁷⁹Br₂ effuse than ⁸¹Br₂?