Question 1

Which of the following is a key assumption of the kinetic molecular theory of gases?

Accepted Answer

The volume of the gas molecules is negligibly small compared to the volume of the container.

Question 2

A sample of oxygen gas at 25°C has a root mean square speed ($$u_{rms}) $$given by which equation?

Accepted Answer

$$u_{rms} = \sqrt{\dfrac{3RT}{M}}$$

Question 3

In the reaction $$2Ag_2O(s) \rightarrow 4Ag(s) + O_2$(g)$$, how many grams of $$Ag_2O$$ are required to produce 4.58 L of $$O_2 at 0.98026 $$atm and 308 K? (Molar mass of $$Ag_2O = 231.47 g/$$mol)

Accepted Answer

Approximately 33.5 g

Question 4

Which statement best explains why helium balloons deflate faster than air-filled balloons?

Accepted Answer

Helium atoms effuse more quickly because they are lighter and move faster.

Question 5

Which of the following is true about elastic collisions in the context of kinetic molecular theory?

Accepted Answer

Total kinetic energy before and after the collision is the same.

Question 6

A student is asked to calculate the volume of hydrogen gas needed to synthesize 35.7 g of methanol ($$CH_3OH) at 355 K $$and 0.97105 atm. Which conceptual steps should they follow?

Accepted Answer

Convert grams of $$CH_3OH to $$moles, use stoichiometric ratio to find moles of $$H_2$$, then use the ideal gas law to find volume.

Question 7

Which equation would you use to determine the number of moles of a gas from its volume, pressure, and temperature?

Accepted Answer

$$PV = nRT$$

Question 8

According to kinetic molecular theory, what happens to the average kinetic energy of gas particles when the temperature is doubled (in Kelvin)?

Accepted Answer

It doubles.

Question 9

Which of the following gases will diffuse the fastest under identical conditions?

Accepted Answer

Helium ($$He)$$

Question 10

A mixture of gases is at high pressure and low temperature. Which statement best describes their behavior?

Accepted Answer

They deviate from ideal gas behavior due to significant intermolecular forces and finite molecular volume.

Question 11

If two gases, $$A$$ and $$B$$, have the same temperature but $$A$$ has a lower molar mass than $$B$$, which statement is correct?

Accepted Answer

Gas $$A$$ molecules move faster than gas $$B$$ molecules.

Question 12

Which of the following best describes effusion?

Accepted Answer

The process by which gas molecules pass through a small hole into a vacuum.

Question 13

A sample of helium gas at 52°C has a molar mass of 4.00 g/mol. What is the correct formula to calculate its root mean square speed ($$u_{rms}$$)?

Accepted Answer

$$u_{rms} = \sqrt{\dfrac{3RT}{M}}$$

Question 14

Which of the following is NOT a basic assumption of the kinetic molecular theory?

Accepted Answer

Gas particles exert attractive forces on each other.

Question 15

In a real-world scenario, why do gases deviate from ideal behavior at low temperatures?

Accepted Answer

Intermolecular forces become significant, causing particles to attract each other.

Question 16

Which of the following reactions is used to synthesize methanol ($$CH_3OH) $$from carbon monoxide and hydrogen?

Accepted Answer

$$CO(g) + 2H_2(g) \rightarrow CH_3OH(g)$$

Question 17

Which of the following best describes the relationship between temperature and the speed of gas particles?

Accepted Answer

As temperature increases, the speed of gas particles increases.

Question 18

Which of the following is a correct statement about diffusion?

Accepted Answer

Diffusion is the process by which gas molecules spread from high concentration to low concentration.

Question 19

A gas sample contains particles of different masses at the same temperature. Which statement is true?

Accepted Answer

All particles have the same average kinetic energy.

Question 20

Which of the following is a real-life consequence of effusion?

Accepted Answer

Helium balloons lose gas and deflate quickly.

Gases – Stoichiometry, Kinetic Molecular Theory, and Gas Properties

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