Question 1

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?

Accepted Answer

A)  0.87 L
B)  4.9 L
C)  1.2 L
D)  2.1 L
E)  1.9 LF) B) and C)
G) None of the above

Question 2

Why does hot air rise?

Accepted Answer

As air is heated,it expands an...

Question 3

The concentration of carbon monoxide in a sample of air is 9.2 ppm.There are ________ molecules of CO in 1.00 L of this air at 755 torr and 23°C.

Accepted Answer

A)  3.8 × 10-7
B)  2.2 × 1021
C)  2.9 × 1018
D)  1.7 × 1020
E)  2.3 × 1017F) B) and E)
G) A) and E)

Question 4

How many grams of KCl(s) are produced from the thermal decomposition of KClO3(s) which produces 50.0 mL of O2(g) at 25°C and 1.00 atm pressure according to the chemical equation shown below?
2 KClO3(s) → 2 KCl(s) + 3 O2(g) ?

Accepted Answer

A)  0.102 g
B)  0.152 g
C)  0.167 g
D)  0.304 gE) None of the above
F) A) and D)

Question 5

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

Accepted Answer

A)  1.17 atm
B)  0.853 atm
C)  1.03 atm
D)  0.969 atm
E)  0.649 atmF) C) and D)
G) A) and C)

Question 6

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

Accepted Answer

A)  N2
B)  O2  
C)  F2
D)  Cl2E) None of the above
F) A) and D)

Question 7

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

Accepted Answer

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

Question 8

A gas sample contains 0.33 atm of Ne,0.45 atm of Ar,and 0.32 atm of CO.What is the total pressure?

Accepted Answer

A)  1.1 atm
B)  1.2 atm
C)  1.0 atm
D)  0.51 atmE) A) and B)
F) B) and D)

Question 9

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

Accepted Answer

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

Question 10

If the pressure in a gas container that is connected to an open-end U-tube manometer is 116 kPa and the pressure of the atmosphere at the open end of the tube is 752 mm Hg,the level of mercury in the tube will

Accepted Answer

A)  be 118 mm higher in the arm open to the atmosphere.
B)  be 118 mm higher in the arm connected to the gas cylinder.
C)  be 870 mm higher in the arm open to the atmosphere.
D)  be 870 mm higher in the arm connected to the gas cylinder.E) All of the above
F) A) and B)

Question 11

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

Accepted Answer

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

Question 12

A balloon filled with helium gas at 20°C occupies 4.91 L at 1.00 atm.The balloon is immersed in liquid nitrogen at -196°C,while the pressure is raised to 5.20 atm.What is the volume of the balloon in the liquid nitrogen?

Accepted Answer

A)  0.25 L
B)  3.6 L
C)  6.7 L
D)  97 LE) B) and C)
F) A) and D)

Question 13

A 1.000 kg sample of nitroglycerine,C3H5N3O9,explodes and releases gases with a temperature of 1985°C at 1.100 atm.What is the volume of gas produced?
4 C3H5N3O9(s) → 12 CO2(g) + 10 H2O(g) + 6 N2(g) + O2(g)

Accepted Answer

A)  742.2 L
B)  3525 L
C)  4730 L
D)  5378 LE) C) and D)
F) B) and D)

Question 14

A balloon contains 0.76 mol N2,0.18 mol O2,0.031 mol He and 0.026 mol H2 at 749 mm Hg.What is the partial pressure of O2?

Accepted Answer

A)  20 mm Hg
B)  23 mm Hg
C)  140 mm Hg
D)  570 mm HgE) A) and B)
F) None of the above

Question 15

Which of the gases in the graph below has the largest molar mass?

Accepted Answer

A)  A
B)  B
C)  C
D)  D
E)  There is not enough information to determine.F) B) and C)
G) C) and D)

Question 16

The density of krypton gas at 1.21 atm and 50.0°C is ________ g/L.

Accepted Answer

A)  0.0456
B)  0.262
C)  0.295
D)  3.82
E)  7.65F) All of the above
G) C) and D)

Question 17

How many molecules of XeF6 are formed from 12.9 L of F2 (at 298 K and 2.60 atm) according to the following reaction? Assume that there is excess Xe. Xe(g) + 3 F2(g) → XeF6(g)

Accepted Answer

A)  1.21 × 1023 molecules XeF6
B)  8.25 × 1023 molecules XeF6
C)  2.75 × 1023 molecules XeF6
D)  7.29 × 1023 molecules XeF6
E)  1.37 × 1023 molecules XeF6F) A) and E)
G) A) and D)

Question 18

What is the temperature of NO2 gas if the average speed (actually the root-mean-square speed) of the molecules is 750 m/s?

Accepted Answer

A)  1.38 K
B)  1.04 × 103 K
C)  1.38 × 103 K
D)  1.04 × 106 KE) B) and C)
F) A) and D)

Question 19

What is the total volume of the mixture of hydrogen gas and oxygen gas can be obtained from the electrolysis of 110.0 grams of water at 25.0°C and 1.00 atm pressure according to the chemical equation shown below?
2 H2O(l) → 2 H2(g) + O2(g)

Accepted Answer

A)  74.7 L
B)  149 L
C)  224 L
D)  447 LE) C) and D)
F) All of the above

Question 20

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

Accepted Answer

A)  1.10 L
B)  2.00 L
C)  2.24 L
D)  3.11 L
E)  1.83 LF) None of the above
G) C) and E)

Exam 5: Gases

A 1.000 kg sample of nitroglycerine,C3H5N3O9,explodes and releases gases with a temperature of 1985°C at 1.100 atm.What is the volume of gas produced? 4 C3H5N3O9(s) → 12 CO2(g) + 10 H2O(g) + 6 N2(g) + O2(g)

Correct AnswerverifiedShow Answer

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

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The concentration of carbon monoxide in a sample of air is 9.2 ppm.There are ________ molecules of CO in 1.00 L of this air at 755 torr and 23°C.

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How many grams of KCl(s) are produced from the thermal decomposition of KClO3(s) which produces 50.0 mL of O2(g) at 25°C and 1.00 atm pressure according to the chemical equation shown below? 2 KClO3(s) → 2 KCl(s) + 3 O2(g) ?

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Which of the gases in the graph below has the largest molar mass?

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What is the total volume of the mixture of hydrogen gas and oxygen gas can be obtained from the electrolysis of 110.0 grams of water at 25.0°C and 1.00 atm pressure according to the chemical equation shown below? 2 H2O(l) → 2 H2(g) + O2(g)

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The density of krypton gas at 1.21 atm and 50.0°C is ________ g/L.

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If the pressure in a gas container that is connected to an open-end U-tube manometer is 116 kPa and the pressure of the atmosphere at the open end of the tube is 752 mm Hg,the level of mercury in the tube will

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

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How many molecules of XeF6 are formed from 12.9 L of F2 (at 298 K and 2.60 atm) according to the following reaction? Assume that there is excess Xe. Xe(g) + 3 F2(g) → XeF6(g)

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

A gas sample contains 0.33 atm of Ne,0.45 atm of Ar,and 0.32 atm of CO.What is the total pressure?

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

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Why does hot air rise?

Correct AnswerverifiedAs air is heated,it expands an...View AnswerShow Answer

A balloon filled with helium gas at 20°C occupies 4.91 L at 1.00 atm.The balloon is immersed in liquid nitrogen at -196°C,while the pressure is raised to 5.20 atm.What is the volume of the balloon in the liquid nitrogen?

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

What is the temperature of NO2 gas if the average speed (actually the root-mean-square speed) of the molecules is 750 m/s?

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

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A balloon contains 0.76 mol N2,0.18 mol O2,0.031 mol He and 0.026 mol H2 at 749 mm Hg.What is the partial pressure of O2?

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A 1.000 kg sample of nitroglycerine,C₃H₅N₃O₉,explodes and releases gases with a temperature of 1985°C at 1.100 atm.What is the volume of gas produced? 4 C₃H₅N₃O₉(s) → 12 CO₂(g) + 10 H₂O(g) + 6 N₂(g) + O₂(g)

Correct Answer
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How many grams of KCl(s) are produced from the thermal decomposition of KClO₃(s) which produces 50.0 mL of O₂(g) at 25°C and 1.00 atm pressure according to the chemical equation shown below? 2 KClO₃(s) → 2 KCl(s) + 3 O₂(g) ?

Correct Answer
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Correct Answer
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What is the total volume of the mixture of hydrogen gas and oxygen gas can be obtained from the electrolysis of 110.0 grams of water at 25.0°C and 1.00 atm pressure according to the chemical equation shown below? 2 H₂O(l) → 2 H₂(g) + O₂(g)

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

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How many molecules of XeF₆are formed from 12.9 L of F₂ (at 298 K and 2.60 atm) according to the following reaction? Assume that there is excess Xe. Xe(g) + 3 F₂(g) → XeF₆(g)

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

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As air is heated,it expands an...
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To what temperature must a balloon,initially at 25^∘C and 2.00 L,be heated in order to have a volume of 6.00 L?

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What is the temperature of NO₂ gas if the average speed (actually the root-mean-square speed) of the molecules is 750 m/s?

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A balloon contains 0.76 mol N₂,0.18 mol O₂,0.031 mol He and 0.026 mol H₂ at 749 mm Hg.What is the partial pressure of O₂?

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