Deck 5: Gases

Question 1

Which one of the following gas laws explains the increase in volume of a basketball upon inflating it at constant temperature and constant pressure?

A) Boyle's law
B) Avogadro's law
C) Charles's law
D) Ideal gas law
E) Inert gas law

Answer 1

Avogadro's law

Question 2

Convert 717.28 mmHg to bar.

A) 1.046 bar
B) 0.9438 bar
C) 1.060 bar
D) 0.9563 bar
E) 0.8971 bar

Answer 2

0.9563 bar

Question 3

The atmospheric pressure is 715 mmHg. What is the pressure in bar?

A) 1.10 bar
B) 0.940 bar
C) 1.08 bar
D) 0.953 bar
E) 0.919 bar

Answer 3

0.953 bar

Question 4

Convert 1.25 atm to bar.

A) 1.23 bar
B) 0.975 bar
C) 1.27 bar
D) 0.7874 bar
E) 1.25 bar

Question 5

The volume of a gas is proportional to number of moles of a gas. What is this known as?

A) Avogadro's law
B) Ideal gas law
C) Charles's law
D) Boyle's law
E) Dalton's law

Question 6

Which one of the gas laws explains why the second floor of a house is usually warmer than the ground floor?

A) Boyle's law
B) Avogadro's law
C) Charles's law
D) Ideal gas law
E) Inert gas law

Question 7

What volume (in mL) will a sample of F₂ gas occupy in a syringe at 5.57 bar if the F₂ has a volume of 25.0 mL at 1.22 bar?

A) 11 mL
B) 17 mL
C) 3.8 mL
D) 5.5 mL
E) 7.6 mL

Question 8

According to Boyle's law, decreasing the volume of a gas sample will result in ________ in the pressure. Boyle's law assumes constant temperature and a constant amount of gas.

A) an increase
B) a decrease
C) no change
D) a decrease and then an increase
E) an increase and then a decrease

Question 9

Convert 3.1473 atm to bar.

A) 4.976 bar
B) 3.189 bar
C) 2.577 bar
D) 4.112 bar
E) 3.875 bar

Question 10

The volume of a gas is proportional to the temperature of a gas. What is this known as?

A) Avogadro's law
B) Ideal gas law
C) Charles's law
D) Boyle's law
E) Dalton's law

Question 11

A gas occupies 3.33 L at 2.23 bar. What is the volume at 2.50 bar?

A) 1.67 L
B) 3.73 L
C) 2.97 L
D) 0.268 L
E) 18.6 L

Question 12

If a sample of 0.29 moles of Ar occupies 3.8 L under certain conditions, what volume will 0.66 moles occupy under the same conditions?

A) 12 L
B) 8.6 L
C) 17 L
D) 5.0 L
E) 15 L

Question 13

Convert 29.592 inches Hg to bar.

A) 0.9889 bar
B) 1.011 bar
C) 1.002 bar
D) 1.023 bar
E) 0.9980 bar

Question 14

According to Avogadro's law, the volume of a gas sample ________ with an increase in the number of moles of gas in the sample. Avogadro's law assumes constant temperature and constant pressure and is independent of the identity of the gas.

A) decreases
B) increases
C) doesn't change
D) increases and then decreases
E) decreases and then increases

Question 15

What volume will a balloon occupy at 1.01 bar if the balloon has a volume of 7.6 L at 3.85 bar?

A) 2.0 L
B) 5.0 L
C) 29 L
D) 35 L
E) 17 L

Question 16

If a scuba diver inhaled air at 3 bar pressure deep in the water and decided to swim back quickly to the surface while holding her breath, what do you expect would happen?

A) The volume of the air in her lungs would increase by a factor of 3.
B) The volume of the air in her lungs would decrease by a factor of 3.
C) The volume of the air in her lungs would increase by a factor of 6.
D) The volume of the air in her lungs would decrease by a factor of 6.
E) The volume of the air in her lungs would not change.

Question 17

The volume of a gas is inversely proportional to the pressure of a gas. What is this known as?

A) Avogadro's law
B) Ideal gas law
C) Charles's law
D) Boyle's law
E) Dalton's law

Question 18

Convert 123.80 kPa to bar.

A) 1.222 bar
B) 1.087 bar
C) 0.8078 bar
D) 0.9186 bar
E) 1.238 bar

Question 19

According to Charles's law, volume of a gas ________ with increasing temperature. Charles's law assumes constant pressure and a constant amount of gas.

A) decreases
B) increases
C) doesn't change
D) increases and then decreases
E) decreases and then increases

Question 20

Convert 4744.1 mmHg to bar.

A) 7.549 bar
B) 5.2423 bar
C) 5.278 bar
D) 6.817 bar
E) 6.325 bar

Question 21

What pressure will 14.0 g of CO exert in a 3.5 L container at 75 °C?

A) 4.1 bar
B) 5.0 bar
C) 6.4 bar
D) 1.1 bar
E) 2.3 bar

Question 22

To what temperature must a balloon, initially at 25 °C and 2.00 L, be heated to have a volume of 6.00 L?

A) 993 K
B) 403 K
C) 75 K
D) 655 K
E) 894 K

Question 23

Calculate the temperature if 3.120 moles of He has a pressure of 2.45 bar in a 23.8 L container.

A) 218 K
B) 314 K
C) 225 K
D) 334 K
E) 287 K

Question 24

To what volume will a sample of gas expand if it is heated from 50.0 °C and 2.33 L to 500.0 °C?

A) 5.58 L
B) 9.74 L
C) 10.3 L
D) 17.9 L
E) 4.38 L

Question 25

What mass of NO₂ is contained in a 13.0 L tank at 4.58 bar and 385 K?

A) 18.8 g
B) 53.1 g
C) 24.4 g
D) 85.6 g
E) 69.2 g

Question 26

Calculate the temperature if 0.0139 moles of Ne has a pressure of 1.237 bar in a 250 mL container.

A) 260 °C
B) 61.8 °C
C) -23.8 °C
D) 15.4 °C
E) -5.57 °C

Question 27

A syringe initially holds a sample of gas with a volume of 285 mL at 355 K and 1.88 bar. To what temperature must the gas in the syringe be heated/cooled to have a volume of 435 mL at 2.50 bar?

A) 139 K
B) 572 K
C) 175 K
D) 466 K
E) 721 K

Question 28

A sample of gas initially has a volume of 859 mL at 565 K and 2.20 bar. What pressure will the sample have if the volume changes to 268 mL while the temperature is increased to 815 K?

A) 10.2 bar
B) 9.83 bar
C) 15.3 bar
D) 6.53 bar
E) 1.05 bar

Question 29

Calculate the temperature, in K, of 2.20 moles of gas occupying 3.50 L at 3.30 bar.

A) 63.1 K
B) 5.25 K
C) 337 K
D) 28.0 K

Question 30

A large balloon is initially filled to a volume of 25.0 L at 353 K and a pressure of 2575 mmHg. What volume of gas will the balloon contain at 1.368 bar and 253 K?

A) 22.2 L
B) 87.5 L
C) 11.4 L
D) 45.0 L
E) 58.6 L

Question 31

An unknown ideal gas was added to an evacuated 775 mL container at a temperature of 267.2 K. If 0.381 moles were added, what is the final pressure?

A) 15.8 bar
B) 12.4 bar
C) 9.92 bar
D) 10.9 bar
E) 8.92 bar

Question 32

If 0.240 mol of He were added to a balloon, how large would the balloon grow? Atmospheric pressure is 0.9871 bar and the ambient temperature is 23.2 °C.

A) 5.99 L
B) 6.54 L
C) 3.73 L
D) 6.49 L
E) 7.28 L

Question 33

A sample of 0.300 moles of nitrogen occupies 0.600 L. Under the same conditions, what number of moles occupies 1.200 L?

A) 0.600 moles
B) 1.50 moles
C) 0.33 moles
D) 6.00 moles

Question 34

What volume would 1.02 moles of Kr occupy at a pressure of 1.65 bar and a temperature of 281.2 K?

A) 28.7 L
B) 14.5 L
C) 12.7 L
D) 6.87 L
E) 16.9 L

Question 35

How many moles of an ideal gas are required to produce a pressure of 3.00 bar in a 1.50 L container with a temperature of 25.0 °C?

A) 0.146 mol
B) 0.0874 mol
C) 0.182 mol
D) 0.914 mol
E) 1.08 mol

Question 36

How many moles of CO are contained in a 5.00 L tank at 155 °C and 2.80 bar?

A) 0.393 moles
B) 1.10 moles
C) 2.51 moles
D) 0.455 moles
E) 0.289 moles

Question 37

A gas is at 35.0 °C and 4.50 L. What is the temperature at 9.00 L?

A) 343°C
B) 70.0°C
C) 616°C
D) 1.16°C
E) 17.5°C

Question 38

A syringe contains 0.65 moles of He gas that occupy 750.0 mL. What volume (in L) of gas will the syringe hold if 0.35 moles of Ne is added?

A) 0.87 L
B) 4.9 L
C) 1.2 L
D) 2.1 L
E) 1.9 L

Question 39

What pressure (in bar) will 0.44 moles of CO₂ exert in a 2.6 L container at 25 °C?

A) 0.35 bar
B) 4.2 bar
C) 4.7 bar
D) 8.6 bar
E) 3.6 bar

Question 40

How many moles of molecular oxygen are required to produce a pressure of 0.413 bar in a 650 mL container with a temperature of 245 K?

A) 0.0132 mol
B) 0.199 mol
C) 0.00872 mol
D) 0.00971 mol
E) 0.0245 mol

Question 41

Which of the following samples will have the greatest volume at STP?

A) 22 g CO
B) 22 g He
C) 22 g O₂
D) 22 g Cl₂
E) All of these samples would have the same volume at STP.

Question 42

Determine the density of gas at 435 K and 1.00 bar.

A) 2.10 g
B) 0.471 g
C) 0.321 g
D) 2.24 g
E) 0.851 g

Question 43

Determine the density of O₃ gas at 341 K and 2.14 bar.

A) 3.62 g
B) 2.91 g
C) 0.321 g
D) 4.82 g
E) 3.17 g

Question 44

Calculate the mass of nitrogen dioxide, N , required if a 5.00 L container is to be filled to 0.6478 bar at a temperature of 1.00 °C.

A) 5.40 g
B) 8.14 g
C) 3.97 g
D) 5.09 g
E) 6.56 g

Question 45

The density of a gas is 1.41 g at STP. What is the gas?

A) Cl₂
B) NH₃
C) O₂
D) Ne

Question 46

Place the following gases in order of increasing density at STP. N₂ NH₃ N₂O₄ Ar

A) N₂O₄ < Ar < N₂ < NH₃
B) Ar < N₂O₄ < N₂ < NH₃
C) N₂ < Ar < N₂O₄ < NH₃
D) NH₃ < N₂ < Ar < N₂O₄
E) Ar < N₂ < NH₃ < N₂O₄

Question 47

Which of the following samples has the greatest density at STP?

A) NO₂
B) Xe
C) SO₂
D) SF₆
E) All of these samples have the same density at STP.

Question 48

What pressure will 2.6 × 10²³ molecules of H₂ exert in a 3.9 L container at 45 °C?

A) 5.7 bar
B) 1.7 bar
C) 2.9 bar
D) 3.4 bar
E) 4.6 bar

Question 49

If 0.3781 g of a gas with a molecular weight of 18.015 g is in a ridged 5.00 L container at 384 K, calculate the final pressure. Assume ideal behaviour.

A) 0.682 bar
B) 0.109 bar
C) 0.0867 bar
D) 0.132 bar
E) 0.0963 bar

Question 50

The density of a gas is 1.146 g at STP. What is the gas?

A) He
B) O₂
C)
D)

Question 51

Determine the density of CO₂ gas at STP.

A) 1.94 g
B) 1.80 g
C) 2.24 g
D) 4.46 g
E) 5.10 g

Question 52

How many molecules of CO₂ are contained in a 10.0 L tank at 7.53 bar and 485 K?

A) 1.89 × 10²⁴ molecules
B) 1.12 × 10²⁴ molecules
C) 8.32 × 10²⁴ molecules
D) 4.89 × 10²⁴ molecules
E) 3.63 × 10²⁴ molecules

Question 53

Give the temperature and pressure at STP.

A) 0° C and 1.00 bar
B) 0 K and 1.00 bar
C) 25° C and 30.00 in Hg
D) 300 K and 1 Torr Hg
E) 0° C and 1 mmHg

Question 54

Which of the following samples will have the lowest pressure if they are all at the same temperature and in identical containers (same volume)?

A) 15 g F₂
B) 15 g Ne
C) 15 g Kr
D) 15 g CO₂
E) All of these samples will have the same pressure.

Question 55

What is the volume of 9.783 × 10²³ atoms of He at 9.25 bar and 512 K?

A) 7.48 L
B) 3.69 L
C) 1.85 L
D) 15.4 L
E) 30.8 L

Question 56

The density of a gas is 3.12 g at STP. What is the gas?

A) Cl₂
B)
C) O₂
D)

Question 57

What is the volume of 5.60 g of O₂ at 7.78 bar and 415 K?

A) 1.53 L
B) 565 L
C) 24.5 L
D) 25.0 L
E) 0.776 L

Question 58

Using the graph below, determine the gas that has the lowest density at STP.

A) A
B) B
C) C
D) D
E) All of the gases have the same density at STP.

Question 59

Which of the following will cause the volume of an ideal gas to triple in value?

A) raising the temperature from 25 °C to 75 °C at constant pressure
B) lowering the absolute temperature by a factor of 3 at constant pressure
C) raising the absolute temperature by a factor of 3 while increasing the pressure by a factor of 3
D) lowering the absolute temperature by a factor of 3 while increasing the pressure by a factor of 3
E) lowering the pressure by a factor of 3 while the temperature stays constant

Question 60

Which of the following gas samples would be most likely to behave ideally under the stated conditions?

A) Ne at STP
B) CO at 200 bar and 25 °C
C) SO₂ at 2 bar and 0 K
D) N₂ at 1 bar and -70 °C
E) O₂ at 400 bar and 25 °C

Question 61

In a container containing CO, H₂, and O₂, what is the mole fraction of CO if the H₂ mole fraction is 0.22 and the O₂ mole fraction is 0.58?

A) 0.20
B) 0.30
C) 0.10
D) 0.50

Question 62

A gas mixture contains CO, Ar, and H₂. What is the total pressure of the mixture if the mole fraction of H₂ is 0.35 and the pressure of H₂ is 0.58 bar?

A) 1.7 bar
B) 0.20 bar
C) 0.49 bar
D) 0.60 bar
E) 2.1 bar

Question 63

A mixture of 0.220 moles CO, 0.350 moles H₂, and 0.640 moles He has a total pressure of 2.95 bar. What is the pressure of CO?

A) 1.86 bar
B) 0.649 bar
C) 0.536 bar
D) 1.54 bar
E) 0.955 bar

Question 64

Define the vapour pressure of water.

A) partial pressure of water in a liquid mixture
B) partial pressure of water in a gaseous mixture
C) condensation of water
D) water dissolved in a liquid
E) water molecules

Question 65

What volume will 4.91 × 10²² atoms of Ne occupy at STP?

A) 1.10 L
B) 2.00 L
C) 2.24 L
D) 3.11 L
E) 1.85 L

Question 66

A compound is found to be 30.45% N and 69.55 % O by mass. If 1.63 g of this compound occupy 389 mL at 0.00 °C and 1.0332 bar, what is the molecular formula of the compound?

A) NO₂
B) N₂O
C) N₄O₂
D) N₂O₅
E) N₂O₄

Question 67

What pressure would a gas mixture in a 10.0 L tank exert if it were composed of 48.5 g He and 94.6 g CO₂ at 398 K?

A) 7.11 bar
B) 39.6 bar
C) 40.1 bar
D) 47.2 bar
E) 58.7 bar

Question 68

Determine the density of gas at 278 K and 1.00 bar.

A) 1.14 g
B) 2.37 g
C) 1.90 g
D) 3.08 g
E) 2.11 g

Question 69

Identify the gas that is the lowest percent by volume in dry air.

A) CO₂
B) Ar
C) O₂
D) N₂

Question 70

Define hypoxia.

A) oxygen starvation
B) increased oxygen concentration in body tissues
C) increased nitrogen concentration in body tissues and fluids
D) nitrogen starvation

Question 71

A gas mixture consists of N₂, O₂, and Ne, where the mole fraction of N₂ is 0.55 and the mole fraction of Ne is 0.25. If the mixture is at STP in a 5.0 L container, how many molecules of O₂ are present?

A) 4.5 × 10²² molecules O₂
B) 2.7 × 10²² molecules O₂
C) 3.7 × 10²³ molecules O₂
D) 1.1 × 10²³ molecules O₂
E) 9.3 × 10²⁴ molecules O₂

Question 72

A 0.334 g sample of an unknown halogen occupies 109 mL at 398 K and 1.43 bar. What is the identity of the halogen?

A) Br₂
B) F₂
C) Cl₂
D) I₂
E) At₂

Question 73

What volume will 0.780 moles of He occupy at STP?

A) 22.4 L
B) 70.0 L
C) 43.7 L
D) 17.7 L
E) 15.6 L

Question 74

A mixture of 10.0 g of Ne and 10.0 g Ar have a total pressure of 1.6 bar. What is the partial pressure of Ne?

A) 1.1 bar
B) 0.80 bar
C) 0.54 bar
D) 0.40 bar
E) 1.3 bar

Question 75

A 0.465 g sample of an unknown compound occupies 245 mL at 298 K and 1.24 bar. What is the molar mass of the unknown compound?

A) 26.3 g
B) 33.9 g
C) 12.2 g
D) 37.9 g
E) 81.8 g

Question 76

A mixture of He, Ne, and Ar has a pressure of 7.85 bar. If the Ne has a mole fraction of 0.47 and Ar has a mole fraction of 0.23, what is the pressure of He?

A) 4.2 bar
B) 3.7 bar
C) 1.8 bar
D) 5.5 bar
E) 2.4 bar

Question 77

A mixture of N₂, O₂, and Ar has mole fractions of 0.25, 0.65, and 0.10, respectively. What is the pressure of N₂ if the total pressure of the mixture is 3.9 bar?

A) 2.5 bar
B) 0.39 bar
C) 0.67 bar
D) 0.98 bar
E) 1.33 bar

Question 78

A syringe contains 589 mL of CO at 325 K and 1.2 bar. A second syringe contains 473 mL of N₂ at 298 K and 2.6 bar. What is the final pressure if the contents of these two syringes are injected into a 1.00 L container at 273 K?

A) 0.59 bar
B) 1.1 bar
C) 1.7 bar
D) 1.9 bar
E) 3.8 bar

Question 79

The following reaction is used to generate hydrogen gas in the laboratory. If 243 mL of gas is collected at 25 °C and has a total pressure of 0.9933 bar, what mass of hydrogen is produced? A possibly useful table of water vapour pressures is provided below. Mg(s) + 2HCl(aq) → MgCl₂(aq) + H₂(g) T (°C) P (bar)
20 0.023398
25 0.031704
30 0.042477

A) 0.0196 g H₂
B) 0.0717 g H₂
C) 0.0190 g H₂
D) 0.0144 g H₂
E) 0.0449 g H₂

Question 80

A mixture of 0.220 moles CO, 0.350 moles H₂, and 0.640 moles He has a total pressure of 2.989 bar. What is the pressure of H₂?

A) 1.17 bar
B) 0.865 bar
C) 1.03 bar
D) 0.969 bar
E) 0.649 bar