Question 1

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 2

Determine the density of CO2 gas at STP.

Accepted Answer

A)  1.94 g  L−1\mathrm { L } ^ { - 1 }L−1 
B)  1.80 g  L−1\mathrm { L } ^ { - 1 }L−1 
C)  2.24 g  L−1\mathrm { L } ^ { - 1 }L−1 
D)  4.46 g  L−1\mathrm { L } ^ { - 1 }L−1 
E)  5.10 g  L−1\mathrm { L } ^ { - 1 }L−1

Question 3

What is the temperature if krypton has a root mean square velocity of 348 m  s−1s ^ { - 1 }s−1  ?

Accepted Answer

A)  800°C
B)  791°C
C)  134°C
D)  604°C
E)  596°C

Question 4

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 5

How many molecules of XeF6 are formed from 12.9 L of F2 (at 298 K and 2.635 bar) according to the following reaction? Assume that there is excess Xe. Xe(g) + 3F2(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 XeF6

Question 6

Name the major gas in dry air.

Accepted Answer

nitrogen o...

Question 7

If 0.3781 g of a gas with a molecular weight of 18.015 g  mol−1\mathrm { mol } ^ { - 1 }mol−1  is in a ridged 5.00 L container at 384 K,calculate the final pressure.Assume ideal behaviour.

Accepted Answer

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

Question 8

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

Accepted Answer

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

Question 9

At what temperature does argon have a root mean square velocity of 492 m s-1?

Accepted Answer

A)  321 K
B)  291 K
C)  340 K
D)  388 K
E)  409 K

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

Determine the total volume of all gases (at STP) formed when 50.0 mL of TNT C3H5(NO3) 3,d = 1.60 g mL-1,molar mass = 227.10 g mol-1) reacts according to the following reaction: 
4C3H5(NO3) 3(l) → 6N2(g) + O2(g) + 12CO2(g) + 10H2O(g)

Accepted Answer

A)  4.93 L
B)  58.0 L
C)  29.6 L
D)  448 L
E)  175 L

Question 12

Why does the rate of effusion increase with a decrease in the molar mass?

Accepted Answer

The rate of effusion depends o...

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

A sample of N2 effuses in 255 s.How long will the same size sample of Cl2 take to effuse?

Accepted Answer

A)  406 s
B)  247 s
C)  645 s
D)  155 s
E)  388 s

Question 15

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?

Accepted Answer

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 16

Why doesn't Dalton's law of partial pressures depend on the identity of the gases present?

Accepted Answer

It is assumed that all gas particles are...

Question 17

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.

Accepted Answer

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

Question 18

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?

Accepted Answer

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

Question 19

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 the answer.

Question 20

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

Exam 5: Gases

Name the major gas in dry air.

Correct Answerverifiednitrogen o...View AnswerShow Answer

If 0.3781 g of a gas with a molecular weight of 18.015 g mol−1\mathrm { mol } ^ { - 1 }mol−1 is in a ridged 5.00 L container at 384 K,calculate the final pressure.Assume ideal behaviour.

Correct AnswerverifiedShow Answer

Determine the total volume of all gases (at STP) formed when 50.0 mL of TNT C3H5(NO3) 3,d = 1.60 g mL-1,molar mass = 227.10 g mol-1) reacts according to the following reaction: 4C3H5(NO3) 3(l) → 6N2(g) + O2(g) + 12CO2(g) + 10H2O(g)

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

At what temperature does argon have a root mean square velocity of 492 m s-1?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

A sample of N2 effuses in 255 s.How long will the same size sample of Cl2 take to effuse?

Correct AnswerverifiedShow Answer

Determine the density of CO2 gas at STP.

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

Why doesn't Dalton's law of partial pressures depend on the identity of the gases present?

Correct AnswerverifiedIt is assumed that all gas particles are...View AnswerShow 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

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?

Correct AnswerverifiedShow Answer

Why does the rate of effusion increase with a decrease in the molar mass?

Correct AnswerverifiedThe rate of effusion depends o...View AnswerShow Answer

How many molecules of XeF6 are formed from 12.9 L of F2 (at 298 K and 2.635 bar) according to the following reaction? Assume that there is excess Xe. Xe(g) + 3F2(g) → XeF6(g)

Correct AnswerverifiedShow Answer

What is the temperature if krypton has a root mean square velocity of 348 m s−1s ^ { - 1 }s−1 ?

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

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.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Correct Answer
verified
nitrogen o...
View Answer

If 0.3781 g of a gas with a molecular weight of 18.015 g $\mathrm { mol } ^ { - 1 }$ is in a ridged 5.00 L container at 384 K,calculate the final pressure.Assume ideal behaviour.

Correct Answer
verified

Determine the total volume of all gases (at STP) formed when 50.0 mL of TNT C₃H₅(NO₃) ₃,d = 1.60 g mL^-1,molar mass = 227.10 g mol^-1) reacts according to the following reaction: 4C₃H₅(NO₃) ₃(l) → 6N₂(g) + O₂(g) + 12CO₂(g) + 10H₂O(g)

Correct Answer
verified

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?

Correct Answer
verified

At what temperature does argon have a root mean square velocity of 492 m s^-1?

Correct Answer
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Correct Answer
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Correct Answer
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A sample of N₂ effuses in 255 s.How long will the same size sample of Cl₂ take to effuse?

Correct Answer
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Determine the density of CO₂ gas at STP.

Correct Answer
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Correct Answer
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Correct Answer
verified
It is assumed that all gas particles are...
View Answer

Correct Answer
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Correct Answer
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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?

Correct Answer
verified

Correct Answer
verified
The rate of effusion depends o...
View Answer

How many molecules of XeF₆are formed from 12.9 L of F₂ (at 298 K and 2.635 bar) according to the following reaction? Assume that there is excess Xe. Xe(g) + 3F₂(g) → XeF₆(g)

Correct Answer
verified

What is the temperature if krypton has a root mean square velocity of 348 m $s ^ { - 1 }$ ?

Correct Answer
verified

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
verified

Correct Answer
verified

Correct Answer
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