Master 28 Gas Law Questions for DAT Exam Preparation

VII. Gases

Gas law questions

There are a total of 28 gas law questions, which are important content-oriented in the summary part of this chapter. Approximately 1 minute is given per question in each test. After the test, if you press the “See Result” button, the results will be displayed along with the answer choices. Red marks indicate incorrect answers and green marks indicate correct answers. Explanations or solutions to the questions are displayed below each question.

GASES TEST 1

1 / 20

The melting point of Manganese, Mn, which is used for industrial metal alloy or stainless steel, is 2,275^oF. Convert this Fahrenheit reading to Kelvin.

A. 1,246 K

B. 1,519 K

C. 2,548 K

D. 4,127 K

E. 4,400 K

Solution:

2 / 20

Which of the following does NOT apply to the Kinetic molecular theory of gases?

A. Van der Waals equation

B. No any force between gas molecules

C. No change of energy from elastic collision

D. Increasing Kinetic energy with increasing temperature

E. Random and straight movement

Explanation:

The kinetic molecular theory of ideal gas can be summarized as “No forces between gas molecules, random and straight movement, negligible size, and elastic collisions.” Van der Waals equation predicts the interaction of molecules of real gases.

3 / 20

The volume of an ideal gas in a cylinder is 44.8L at 4 atm. What is the pressure of this gas if a piston compresses its volume to 22.4L?

A. 2 atm

B. 6 atm

C. 16 atm

D. 3,040 mmHg

E. 6,080 mmHg

Solution:

4 / 20

4.4L of sample of air in a container is cooled from 27^oC to 0^oC. What is the final volume of this air?

A. 0.16L

B. 2.0L

C. 4.0L

D. 4.8L

E. 118.8L

Solution:

5 / 20

The pressure of an unknown gas in a cylinder was 30 atm at 240K. What is the torr of this gas when the temperature of this gas is heated to 400K?

A. 50 torr

B. 144 torr

C. 7,200 torr

D. 38,000 torr

E. 109,440 torr

Solution:

6 / 20

The initial temperature of an unknown gas is placed in a 2L container is 25^oC at 3atm. If the condition of the gas is changed to 12atm and 1L of volume, what is the new temperature?

A. 50°C

B. 149K

C. 298K

D. 323°C

E. 596°C

Solution:

7 / 20

The pressure of a gas in a balloon is 2 atm with a volume of 200L at 27 ^oC. What is the volume of the gas when the pressure of the balloon is changed to 4 atm at 47 ^oC?

A. 53.4 L

B. 57.4 L

C. 106.7 L

D. 114.8 L

E. 213.4 L

Solution:

8 / 20

6 mole of CO₂ is contained in 3L of a cylinder at 2.0atm pressure. When 3 mole of this gas is contained in 6L of the cylinder with the same temperature, what is the pressure of this gas?

A. 0.1 atm

B. 0.2 atm

C. 0.5 atm

D. 1.0 atm

E. 2.0 atm

Solution:

9 / 20

96g of a gas is contained in a 73.8 L cylinder at 27^oC. The pressure is 760 mmHg. What is the gas? (Gas constant, R = o.o82 atm•L/ mol•K).

A. He

B. Ne

C. H₂

D. O₂

E. CO₂

Solution:

10 / 20

Which of the following gases has the highest temperature at a constant pressure?

A. 40g of Ar

B. 2g of He

C. 22g of CO₂

D. 56g of CO

E. 7g of Cl₂

Solution:

11 / 20

2 mol of O₂, 1 mol of CO_2,and 3mol of N₂ are contained in 20L of a flask at 0^oC. What is the total pressure of this gas mixture?

A. 1.12 atm

B. 2.24 atm

C. 3.36 atm

D. 5.60 atm

E. 6.72 atm

Solution:

12 / 20

When 32g of methane and 44g of carbon dioxide are contained in a 44.8L cylinder, the total pressure is 5 atm. What is the temperature of the gas mixture in this cylinder?

A. 911 K

B. 2732 K

C. 1366 K

D. 455 K

E. 683 K

Solution:

13 / 20

If 34g of NH₃ gas is placed in a 44.8L container at a pressure of 1000mmHg, what is the temperature of NH₃?

A. 21.1K

B. 86.4°C

C. 254.3K

D. 15795°C

E. 273170.0K

Solution:

14 / 20

What is the density (g/L) of 3.0 atm of CO₂ at a room temperature of 27 ^oC? ( R= 1.0 atm•L/mol•K)

A. 8.8

B. 4.4

C. 2.2

D. 0.88

E. 0.44

Solution:

15 / 20

The density of O₂ is 4.3 g/L at 0^oC. What is the pressure?

A. 1.0 atm

B. 2.0 atm

C. 3.0 atm

D. 4.0 atm

E. 6.0 atm

Solution:

16 / 20

The density of unknown gas is 3.2g/L at STP. What is this gas?

A. Hydrogen

B. Neon

C. Fluorine

D. Chlorine

E. Methane

Solution:

17 / 20

The density of 56g of an unknown gas at STP is 5.0 g/L. How many molecules of this gas are present?

A. 3.01×10²³

B. 6.02×10²³

C. 1.20×10²⁴

D. 2.02×10²⁴

E. 4.80×10²⁵

Solution:

18 / 20

Which of the following gases has the highest speed?

A. SO₂

B. Cl₂

C. N₂

D. Ar

E. CO₂

Solution:

19 / 20

Which of the following two gases has the highest ratio of diffusion?

A. H₂ and He

B. H₂ and Ar

C. CO₂ and He

D. He and N₂

E. H₂ and O₂

Solution:

20 / 20

Find the molecular mass of an unknown gas that is 2 times faster than SO₂.

A. 4 g/mol

B. 16 g/mol

C. 32 g/mol

D. 128 g/mol

E. 256 g/mol

Solution:

Your score is

The average score is 35%

GASES TEST 2

1 / 8

When the stopcock is opened, what is the partial pressure of gas A?

A. 0.6 atm

B. 0.9 atm

C. 1.0 atm

D. 1.2 atm

E. 3.0 atm

Solution:

2 / 8

When this stopcock is opened, what is the total pressure of the gas mixture?

A. 0.9 atm

B. 1.2 atm

C. 1.5 atm

D. 1.8 atm

E. 2.5 atm

Solution:

3 / 8

A gas mixture of 2 mol of H₂, 3mol of NH_3,and 4 mol of O₂ is contained in a flask at a total pressure of 7 atm. What is the partial pressure of H₂?

A. 0.22 atm

B. 1.54 atm

C. 3.08 atm

D. 15.9 atm

E. 31.8 atm

Solution:

4 / 8

A gas mixture of 28g of CO, 34g of NH₃, and 10g of H₂ is contained in a flask of 5L. What is the total pressure when the partial pressure of NH₃is 5 atm?

A. 1.25 atm

B. 2.36 atm

C. 10.6 atm

D. 20.0 atm

E. 40.0 atm

Solution:

5 / 8

What is the mole fraction of N₂if a gas mixture has partial pressures of 3 atm of N₂ and 5 atm of CO₂?

A. 0.37

B. 0.63

C. 0.83

D. 1.60

E. 2.67

Solution:

6 / 8

The chemical reaction below is used for an air bag in a car. When the car is bumped, the air bag, by producing N₂gas, inflates and saves the life of a driver. If the gas N₂ is produced at a volume of 44.8L at STP, how many grams of NaN₃ are used for the air bag?

2NaN₃(s) → 2Na(s) + 3N₂(g)

A. 43.3 g

B. 86.5 g

C. 129.9 g

D. 173.0 g

E. 259.5 g

Solution: