Question 1

The density of a gas is 3.12 g L-1 at STP. What is the gas?

Accepted Answer

A)  Cl2
B)  O3
C)  O2
D)  F2

Question 2

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

Accepted Answer

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

Question 3

When 14.0 g of zinc metal reacts with excess HCl, how many litres of H2 gas are produced at STP? Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)

Accepted Answer

A)  0.208 L
B)  0.416 L
C)  4.86 L
D)  9.60 L

Question 4

Convert 123.80 kPa to bar.

Accepted Answer

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

Question 5

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?

Accepted Answer

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

Question 6

Determine the density of NH3 gas at 435 K and 1.00 bar.

Accepted Answer

A)  2.10 g L-1
B)  0.471 g L-1
C)  0.321 g L-1
D)  2.24 g L-1
E)  0.851 g L-1

Question 7

The mole fraction of oxygen in dry air near sea level is 0.20948. The concentration of oxygen is ________ molecules per litre, assuming an atmospheric pressure of 0.985 bar and a temperature of 29.5 °C.

Accepted Answer

A)  6.23
B)  0.00819
C)  4.94 × 1021
D)  3.75 × 1024
E)  5.07 × 1022

Question 8

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

Accepted Answer

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

Question 9

How many grams of calcium hydride are required to produce 4.56 L of hydrogen gas at 25.0 °C and 0.975 bar according to the chemical equation shown below? CaH2(s) + 2H2O(l) → Ca(OH) 2(aq) + 2H2(g)

Accepted Answer

A)  3.77 g
B)  7.64 g
C)  15.3 g
D)  45.6 g

Question 10

Which of the following gases has the highest average speed at 400 K?

Accepted Answer

A)  N2
B)  O2  
C)  F2
D)  Cl2

Question 11

If CO2 and NH3 are allowed to effuse through a porous membrane under identical conditions, the rate of effusion for NH3 will be ________ times that of CO.

Accepted Answer

A)  0.39
B)  0.62
C)  1.6
D)  2.6

Question 12

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

Accepted Answer

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

Question 13

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?

Accepted Answer

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

Question 14

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

Accepted Answer

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

Question 15

What volume will 0.780 moles of He occupy at STP?

Accepted Answer

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

Question 16

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?

Accepted Answer

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

Question 17

What is the Celsius temperature of 100.0 g of chlorine gas in a 55.0 L container at 1.069 bar?

Accepted Answer

A)  -23°C
B)  228°C
C)  250°C
D)  500°C

Question 18

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

Accepted Answer

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

Question 19

Determine the mass of water formed when 12.5 L NH3 (at 298 K and 1.50 bar) is reacted with 18.9 L of O2 (at 323 K and 1.1 bar) . 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g)

Accepted Answer

A)  16.7 g H2O
B)  20.7 g H2O
C)  37.7 g H2O
D)  13.8 g H2O
E)  27.9 g H2O

Question 20

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?

Accepted Answer

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

Exam 5: Gases

What volume will 0.780 moles of He occupy at STP?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

Determine the density of NH3 gas at 435 K and 1.00 bar.

Correct AnswerverifiedShow Answer

Determine the mass of water formed when 12.5 L NH3 (at 298 K and 1.50 bar) is reacted with 18.9 L of O2 (at 323 K and 1.1 bar) . 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g)

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

How many grams of calcium hydride are required to produce 4.56 L of hydrogen gas at 25.0 °C and 0.975 bar according to the chemical equation shown below? CaH2(s) + 2H2O(l) → Ca(OH) 2(aq) + 2H2(g)

Correct AnswerverifiedShow Answer

The density of a gas is 3.12 g L-1 at STP. What is the gas?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

If CO2 and NH3 are allowed to effuse through a porous membrane under identical conditions, the rate of effusion for NH3 will be ________ times that of CO.

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

The mole fraction of oxygen in dry air near sea level is 0.20948. The concentration of oxygen is ________ molecules per litre, assuming an atmospheric pressure of 0.985 bar and a temperature of 29.5 °C.

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

Convert 123.80 kPa to bar.

Correct AnswerverifiedShow Answer

What is the Celsius temperature of 100.0 g of chlorine gas in a 55.0 L container at 1.069 bar?

Correct AnswerverifiedShow Answer

When 14.0 g of zinc metal reacts with excess HCl, how many litres of H2 gas are produced at STP? Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)

Correct AnswerverifiedShow Answer

Which of the following gases has the highest average speed at 400 K?

Correct AnswerverifiedShow Answer

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Determine the density of NH₃ gas at 435 K and 1.00 bar.

Correct Answer
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Determine the mass of water formed when 12.5 L NH₃ (at 298 K and 1.50 bar) is reacted with 18.9 L of O₂ (at 323 K and 1.1 bar) . 4NH₃(g) + 5O₂(g) → 4NO(g) + 6H₂O(g)

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

Correct Answer
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How many grams of calcium hydride are required to produce 4.56 L of hydrogen gas at 25.0 °C and 0.975 bar according to the chemical equation shown below? CaH₂(s) + 2H₂O(l) → Ca(OH) ₂(aq) + 2H₂(g)

Correct Answer
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The density of a gas is 3.12 g L^-1 at STP. What is the gas?

Correct Answer
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Correct Answer
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If CO₂ and NH₃ are allowed to effuse through a porous membrane under identical conditions, the rate of effusion for NH₃ will be ________ times that of CO.

Correct Answer
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When 14.0 g of zinc metal reacts with excess HCl, how many litres of H₂ gas are produced at STP? Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g)

Correct Answer
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Correct Answer
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