Question 1

What is the molar mass of an unknown gas if 3.7 g of the gas occupies 450 mL at 20.0°C and 2.0 atm? The value of R = 0.0821 L atm mol-1 K-1.

Accepted Answer

A)  3.7 × 10-2 g/mol 
B)  9.9 × 10-3 g/mol 
C)  6.8 g/mol 
D)  98.9 g/mol 
E)  5.5 × 103 g/mol 
A)  3.7 × 10-2 g/mol 
B)  9.9 × 10-3 g/mol 
C)  6.8 g/mol 
D)  98.9 g/mol 
E)  5.5 × 103 g/mol

Question 2

At 20°C, a sample of gas has a volume of 2.51 L at 795 torr. What is the new pressure (in atm) if the volume is increased to 6.46 L at the same temperature?

Accepted Answer

A)  2.69 atm 
B)  0.813 atm 
C)  0.406 atm 
D)  309 atm 
E)  2050 atm 
A)  2.69 atm 
B)  0.813 atm 
C)  0.406 atm 
D)  309 atm 
E)  2050 atm

Question 3

A balloon filled with gas is heated from 30.0°C to 197.0°C at constant pressure. If the original volume of the balloon was 1.560 L, what is the volume (in L) of the gas after heating?

Accepted Answer

A)  0.238 L 
B)  1.02 L 
C)  1.01 L 
D)  2.42 L 
E)  10.2 L 
A)  0.238 L 
B)  1.02 L 
C)  1.01 L 
D)  2.42 L 
E)  10.2 L

Question 4

Which is a mathematical representation of Charles's Law?

Accepted Answer

A)  P/T = constant 
B)  PV = constant 
C)  V × T = constant 
D)  n × T = constant 
E)  V/T = constant 
A)  P/T = constant 
B)  PV = constant 
C)  V × T = constant 
D)  n × T = constant 
E)  V/T = constant

Question 5

What happens to a helium balloon at a party on a hot day if the balloon was filled on a cold morning?

Accepted Answer

A)  The balloon shrinks because the warmer day temperature speeds up the helium atoms and increases the number of atoms that escape through the inner wall of the balloon. 
B)  The balloon expands because the warmer day temperature causes the helium atoms to be less attracted to each other and allows them to occupy more space inside the balloon. 
C)  The balloon expands because the warmer day temperature speeds up the helium atoms and increases the force and frequency of gas collisions on the inner wall of the balloon. 
D)  The balloon shrinks because the warmer day temperature causes the helium atoms to be more attracted to each other and allows them to occupy less space inside the balloon. 
E)  The balloon keeps the same volume because the amount of gas inside the balloon does not change. 
A)  The balloon shrinks because the warmer day temperature speeds up the helium atoms and increases the number of atoms that escape through the inner wall of the balloon. 
B)  The balloon expands because the warmer day temperature causes the helium atoms to be less attracted to each other and allows them to occupy more space inside the balloon. 
C)  The balloon expands because the warmer day temperature speeds up the helium atoms and increases the force and frequency of gas collisions on the inner wall of the balloon. 
D)  The balloon shrinks because the warmer day temperature causes the helium atoms to be more attracted to each other and allows them to occupy less space inside the balloon. 
E)  The balloon keeps the same volume because the amount of gas inside the balloon does not change.

Question 6

Determine the volume (in L) of Cl2(g) required to carry out the following reaction at 794 torr and 625°C using 15.0 g of Fe. The value of R = 0.0821 L atm mol-1 K-1.

Accepted Answer

A)  1.06 × 103 L 
B)  0.0374 L 
C)  19.0 L 
D)  19.8 L 
E)  28.4 L 
A)  1.06 × 103 L 
B)  0.0374 L 
C)  19.0 L 
D)  19.8 L 
E)  28.4 L

Question 7

For a gas mixture

Accepted Answer

A)  the partial pressures of the gases at equilibrium are equal. 
B)  the total pressure is equal to the maximum partial pressure. 
C)  the total pressure is equal to the sum of the partial pressures. 
D)  the lightest gas will have the lowest partial pressure. 
E)  the lightest gas will have the highest partial pressure. 
A)  the partial pressures of the gases at equilibrium are equal. 
B)  the total pressure is equal to the maximum partial pressure. 
C)  the total pressure is equal to the sum of the partial pressures. 
D)  the lightest gas will have the lowest partial pressure. 
E)  the lightest gas will have the highest partial pressure.

Question 8

A 5.00 L flask contains 3.50 g of sulfur trioxide, 2.45 g of carbon monoxide, and 3.99 g of argon all at 35°C. What is the pressure (in atm) in the flask?

Accepted Answer

A)  0.221 atm 
B)  0.234 atm 
C)  50.5 atm 
D)  5.70 atm 
E)  1.17 atm 
A)  0.221 atm 
B)  0.234 atm 
C)  50.5 atm 
D)  5.70 atm 
E)  1.17 atm

Question 9

Under what conditions do real gases most closely approximate the behavior of ideal gases?

Accepted Answer

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

Question 10

Suppose that 1.00 gram of each of the three inert gases, Ne, Ar, Kr, are combined in a 1.00-L flask at 25.0°C. Determine the partial pressures of each of the three gases in the flask in torr. Ne Ar Kr Total

Accepted Answer

A)  1.21 torr 0.612 torr 0.292 torr 2.12 torr 
B)  24.4 torr 24.4 torr 24.4 torr 73.2 torr 
C)  922 torr 466 torr 222 torr 923 torr 
D)  922 torr 466 torr 222 torr 1.61 × 103 torr 
E)  1.86 × 104 torr 1.86 × 104 torr 1.86 × 104 torr 5.58 × 103 torr 
A)  1.21 torr 0.612 torr 0.292 torr 2.12 torr 
B)  24.4 torr 24.4 torr 24.4 torr 73.2 torr 
C)  922 torr 466 torr 222 torr 923 torr 
D)  922 torr 466 torr 222 torr 1.61 × 103 torr 
E)  1.86 × 104 torr 1.86 × 104 torr 1.86 × 104 torr 5.58 × 103 torr

Question 11

The following is the reaction that occurs in automobile airbags:   How many grams of sodium azide (NaN3) are required to produce 19.00 L of N2 at 293K and 775 mm Hg? R = 0.0821 L atm mol-1 K-1.

Accepted Answer

A)  34.9 g 
B)  52.0 g 
C)  2.66 × 104 g 
D)  3.89 × 105 g 
E)  5.80 × 105 g 
A)  34.9 g 
B)  52.0 g 
C)  2.66 × 104 g 
D)  3.89 × 105 g 
E)  5.80 × 105 g

Question 12

Which is not a greenhouse gas?

Accepted Answer

A)  carbon dioxide 
B)  methane 
C)  ozone 
D)  water vapor 
E)  nitrogen 
A)  carbon dioxide 
B)  methane 
C)  ozone 
D)  water vapor 
E)  nitrogen

Question 13

If 7.63 g of an unknown gas occupies 79.1 mL at 25.02°C and 7.55 atm of pressure, what is the molar mass of the gas? The value of R = 0.0821 L atm mol-1 K-1.

Accepted Answer

A)  3.21 × 10-3 g/mol 
B)  0.312 g/mol 
C)  26.2 g/mol 
D)  31.2 g/mol 
E)  312 g/mol 
A)  3.21 × 10-3 g/mol 
B)  0.312 g/mol 
C)  26.2 g/mol 
D)  31.2 g/mol 
E)  312 g/mol

Question 14

If a 2.0-liter sample of gas experiences a decrease in pressure from 1.74 atm to 0.555 atm at 25°C, what is the resulting volume (in L) at 25°C?

Accepted Answer

A)  0.48 L 
B)  0.64 L 
C)  1.9 L 
D)  6.3 L 
E)  20 L 
A)  0.48 L 
B)  0.64 L 
C)  1.9 L 
D)  6.3 L 
E)  20 L

Question 15

Which two assumptions of the Kinetic-Molecular Theory need to be altered to account for the behavior of real gases?
I. gas molecules have no volume
II. gas molecules move in random motion
III. gas molecules undergo no attractive or repulsive force toward one another
IV. gas molecules undergo perfectly elastic collision

Accepted Answer

A)  I and II 
B)  I and III 
C)  II and III 
D)  II and IV 
E)  III and IV 
A)  I and II 
B)  I and III 
C)  II and III 
D)  II and IV 
E)  III and IV

Question 16

Which description of ideal gases and real gases is true?

Accepted Answer

A)  The molecules in an ideal gas occupy more space than the molecules in a real gas. 
B)  The measured pressure for ideal gases is smaller than for real gases. 
C)  Gaseous atoms of helium and argon behave the same as real gases but differently as ideal gases. 
D)  The forces of attraction between molecules are greater in an ideal gas than in a real gas. 
E)  The van der Waals equation is the same as the ideal gas law in some cases. 
A)  The molecules in an ideal gas occupy more space than the molecules in a real gas. 
B)  The measured pressure for ideal gases is smaller than for real gases. 
C)  Gaseous atoms of helium and argon behave the same as real gases but differently as ideal gases. 
D)  The forces of attraction between molecules are greater in an ideal gas than in a real gas. 
E)  The van der Waals equation is the same as the ideal gas law in some cases.

Question 17

Which statement is false?

Accepted Answer

A)  Atmospheric gases are an example of gases mixing completely. 
B)  An exhaled breath of air will disperse throughout the entire atmosphere. 
C)  A gas inside a container will remain inside if the container is opened. 
D)  Atmospheric pressure is a result of gas molecules exerting pressure on their surroundings. 
E)  An air pump demonstrates that gases can be compressed. 
A)  Atmospheric gases are an example of gases mixing completely. 
B)  An exhaled breath of air will disperse throughout the entire atmosphere. 
C)  A gas inside a container will remain inside if the container is opened. 
D)  Atmospheric pressure is a result of gas molecules exerting pressure on their surroundings. 
E)  An air pump demonstrates that gases can be compressed.

Question 18

What is the pressure (in atm) exerted by a 2.00 mole sample of gas that occupies 2.50 L at 307.15 K? The value of R = 0.0821 L atm mol-1 K-1.

Accepted Answer

A)  40.3 atm 
B)  20.2 atm 
C)  80.7 atm 
D)  0.0496 atm 
E)  38.1 atm 
A)  40.3 atm 
B)  20.2 atm 
C)  80.7 atm 
D)  0.0496 atm 
E)  38.1 atm

Question 19

Convert 699 torr to 
1) atm
2) mmHg
3) kPa.

Accepted Answer

The answer of Convert 699 torr to 
1) atm
2) mmHg
3)...

Question 20

What conditions are referred to as standard temperature and pressure (STP) for gas behavior?

Accepted Answer

A)  0°C and 1 atm 
B)  0°C and 1 mm Hg 
C)  273°C and 1 atm 
D)  25°C and 1 atm 
E)  298 K and 760 torr 
A)  0°C and 1 atm 
B)  0°C and 1 mm Hg 
C)  273°C and 1 atm 
D)  25°C and 1 atm 
E)  298 K and 760 torr

What is the molar mass of an unknown gas if 3.7 g of the gas occupies 450 mL at 20.0°C and 2.0 atm? The value of R = 0.0821 L atm mol^-1 K^-1.

At 20°C, a sample of gas has a volume of 2.51 L at 795 torr. What is the new pressure (in atm) if the volume is increased to 6.46 L at the same temperature?

A balloon filled with gas is heated from 30.0°C to 197.0°C at constant pressure. If the original volume of the balloon was 1.560 L, what is the volume (in L) of the gas after heating?

Which is a mathematical representation of Charles's Law?

What happens to a helium balloon at a party on a hot day if the balloon was filled on a cold morning?

Determine the volume (in L) of Cl₂(g) required to carry out the following reaction at 794 torr and 625°C using 15.0 g of Fe. The value of R = 0.0821 L atm mol^-1 K^-1.

For a gas mixture

A 5.00 L flask contains 3.50 g of sulfur trioxide, 2.45 g of carbon monoxide, and 3.99 g of argon all at 35°C. What is the pressure (in atm) in the flask?

Under what conditions do real gases most closely approximate the behavior of ideal gases?

Suppose that 1.00 gram of each of the three inert gases, Ne, Ar, Kr, are combined in a 1.00-L flask at 25.0°C. Determine the partial pressures of each of the three gases in the flask in torr. Ne Ar Kr Total

The following is the reaction that occurs in automobile airbags: How many grams of sodium azide (NaN₃) are required to produce 19.00 L of N₂ at 293K and 775 mm Hg? R = 0.0821 L atm mol^-1 K^-1.

Which is not a greenhouse gas?

If 7.63 g of an unknown gas occupies 79.1 mL at 25.02°C and 7.55 atm of pressure, what is the molar mass of the gas? The value of R = 0.0821 L atm mol^-1 K^-1.

If a 2.0-liter sample of gas experiences a decrease in pressure from 1.74 atm to 0.555 atm at 25°C, what is the resulting volume (in L) at 25°C?

Which description of ideal gases and real gases is true?

Which statement is false?

What is the pressure (in atm) exerted by a 2.00 mole sample of gas that occupies 2.50 L at 307.15 K? The value of R = 0.0821 L atm mol^-1 K^-1.

Convert 699 torr to 1) atm 2) mmHg 3) kPa.

What conditions are referred to as standard temperature and pressure (STP) for gas behavior?

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Additional Aqueous Equilibria

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Exam 10: Gases and the Atmosphere

What is the molar mass of an unknown gas if 3.7 g of the gas occupies 450 mL at 20.0°C and 2.0 atm? The value of R = 0.0821 L atm mol-1 K-1.

At 20°C, a sample of gas has a volume of 2.51 L at 795 torr. What is the new pressure (in atm) if the volume is increased to 6.46 L at the same temperature?

A balloon filled with gas is heated from 30.0°C to 197.0°C at constant pressure. If the original volume of the balloon was 1.560 L, what is the volume (in L) of the gas after heating?

Which is a mathematical representation of Charles's Law?

What happens to a helium balloon at a party on a hot day if the balloon was filled on a cold morning?

Determine the volume (in L) of Cl2(g) required to carry out the following reaction at 794 torr and 625°C using 15.0 g of Fe. The value of R = 0.0821 L atm mol-1 K-1.

For a gas mixture

A 5.00 L flask contains 3.50 g of sulfur trioxide, 2.45 g of carbon monoxide, and 3.99 g of argon all at 35°C. What is the pressure (in atm) in the flask?

Under what conditions do real gases most closely approximate the behavior of ideal gases?

Suppose that 1.00 gram of each of the three inert gases, Ne, Ar, Kr, are combined in a 1.00-L flask at 25.0°C. Determine the partial pressures of each of the three gases in the flask in torr. Ne Ar Kr Total

The following is the reaction that occurs in automobile airbags: How many grams of sodium azide (NaN3) are required to produce 19.00 L of N2 at 293K and 775 mm Hg? R = 0.0821 L atm mol-1 K-1.

Which is not a greenhouse gas?

If 7.63 g of an unknown gas occupies 79.1 mL at 25.02°C and 7.55 atm of pressure, what is the molar mass of the gas? The value of R = 0.0821 L atm mol-1 K-1.

If a 2.0-liter sample of gas experiences a decrease in pressure from 1.74 atm to 0.555 atm at 25°C, what is the resulting volume (in L) at 25°C?

Which description of ideal gases and real gases is true?

Which statement is false?

What is the pressure (in atm) exerted by a 2.00 mole sample of gas that occupies 2.50 L at 307.15 K? The value of R = 0.0821 L atm mol-1 K-1.

Convert 699 torr to 1) atm 2) mmHg 3) kPa.

What conditions are referred to as standard temperature and pressure (STP) for gas behavior?

The Nature of Chemistry

Atoms and Elements

Chemical Compounds

Quantities of Reactants and Products

Chemical Reactions

Energy and Chemical Reactions

Electron Configurations and the Periodic Table

Covalent Bonding

Molecular Structure

Liquids, Solids, and Materials

Chemical Kinetics: Rates of Reactions

Chemical Equilibrium

The Chemistry of Solutes and Solutions

Acids and Bases

Additional Aqueous Equilibria

Thermodynamics: Directionality of Chemical Reactions

Electrochemistry and Its Applications

Nuclear Chemistry

Filters

What is the molar mass of an unknown gas if 3.7 g of the gas occupies 450 mL at 20.0°C and 2.0 atm? The value of R = 0.0821 L atm mol^-1 K^-1.

Determine the volume (in L) of Cl₂(g) required to carry out the following reaction at 794 torr and 625°C using 15.0 g of Fe. The value of R = 0.0821 L atm mol^-1 K^-1.

The following is the reaction that occurs in automobile airbags: How many grams of sodium azide (NaN₃) are required to produce 19.00 L of N₂ at 293K and 775 mm Hg? R = 0.0821 L atm mol^-1 K^-1.

If 7.63 g of an unknown gas occupies 79.1 mL at 25.02°C and 7.55 atm of pressure, what is the molar mass of the gas? The value of R = 0.0821 L atm mol^-1 K^-1.

What is the pressure (in atm) exerted by a 2.00 mole sample of gas that occupies 2.50 L at 307.15 K? The value of R = 0.0821 L atm mol^-1 K^-1.