Question 1

A scuba diver fills a tank with air at a pressure of 200 atm. If the atmospheric pressure at sea level is 1 atm, what is the pressure in the tank in Pascals (Pa)? (1 atm = 101325 Pa)

Accepted Answer

$$2.03 	imes 10^6$ Pa

Question 2

Which of the following statements best describes why gases have low densities compared to solids and liquids?

Accepted Answer

Gas particles are far apart with negligible interactions.

Question 3

A 2.0 L sample of oxygen gas is at 1.0 atm and 300 K. If the volume is decreased to 1.0 L at constant temperature, what is the new pressure?

Accepted Answer

$$2.0$$ atm

Question 4

Which property of gases allows a helium-filled balloon to expand as it is heated, assuming constant pressure?

Accepted Answer

Volume of a gas increases with temperature at constant pressure (Charles's Law).

Question 5

A 1.0 L rigid cylinder contains a gas at 100 °C and 775 mmHg. How many moles of gas are present? ($$R = 0.0821 L$$·atm·mol$$^{-1}$$·K$$^{-1}$$, $$1$$ atm $$= 760$$ mmHg)

Accepted Answer

$$0.033$$ mol

Question 6

Which of the following best explains why water boils at a lower temperature in the mountains than at sea level?

Accepted Answer

Atmospheric pressure is lower at higher altitudes.

Question 7

A sample of gas at 2.0 atm and 273 K has a volume of 4.0 L. If the pressure is reduced to 1.0 atm at constant temperature, what is the new volume?

Accepted Answer

$$8.0 L$$

Question 8

Which of the following is NOT an assumption of the kinetic-molecular theory of gases?

Accepted Answer

Gas particles experience strong attractive forces.

Question 9

A barometer measures atmospheric pressure as the height of a mercury column. What is the height (in mmHg) at exactly 1 atm?

Accepted Answer

760 mmHg

Question 10

A 0.140 mol sample of O$$_2$$ gas occupies 12.0 L at 600 mmHg and 273 K. If the volume is changed to 36.0 L at constant temperature and moles, what is the new pressure?

Accepted Answer

$$200$$ mmHg

Question 11

Which of the following gases exists as a monatomic species at room temperature and 1 atm?

Accepted Answer

Ne

Question 12

A mixture of He, Ar, and Ne has a total pressure of 558 Torr. If the partial pressures of He and Ne are 341 Torr and 112 Torr, respectively, what is the partial pressure of Ar?

Accepted Answer

105 Torr

Question 13

Which variable must be in Kelvin for all gas law calculations?

Accepted Answer

Temperature

Question 14

A 1.0 L flexible container of gas at 300 K and 1.0 atm contains 0.10 mol of gas. If the temperature is increased to 600 K and the pressure to 4.0 atm, what is the new volume?

Accepted Answer

$$0.50 L$$

Question 15

Which law describes the relationship between the volume and temperature of a gas at constant pressure and moles?

Accepted Answer

Charles's Law

Question 16

A sample of gas at constant pressure has a volume of 2.80 L at an unknown temperature. When cooled to 0 °C, its volume decreases to 2.57 L. What was the initial temperature in °C?

Accepted Answer

$$20$$ °C

Question 17

Which of the following best describes the partial pressure of a gas in a mixture?

Accepted Answer

It is the pressure the gas would exert if it were alone in the container.

Question 18

What is the molar volume of an ideal gas at STP (Standard Temperature and Pressure)?

Accepted Answer

22.4 L

Question 19

A gas in a closed flexible container at 273 K is at an initial pressure $$P_1$$ and volume $$V_1. If $$the volume is decreased by half at constant temperature, what happens to the pressure?

Accepted Answer

It doubles.

Question 20

Which of the following is a correct rearrangement of the ideal gas law to solve for the number of moles, $$n$$?

Accepted Answer

$$n = \dfrac{P V}{R T}$$

Gases: Properties, Laws, and Applications (Chapter 8 Study Notes)

Guida di studio - Domande di pratica

Study guide - Flashcard