Question 1

A scuba diver at a depth of 20 m breathes air at a pressure of 3 atm. If the diver fills his lungs with 5.0 L of air at this depth and then ascends to the surface (1 atm) without exhaling, what will be the final volume of air in his lungs? (Assume temperature is constant.)

Accepted Answer

$$15.0\ \mathrm{L}$$

Question 2

Which of the following best explains why gases are compressible, but liquids are not, according to the kinetic molecular theory?

Accepted Answer

There is a lot of empty space between gas particles compared to liquids.

Question 3

A sample of gas occupies $$2.80\ \mathrm{L} at an $$unknown temperature. When cooled to $$0\ ^\circ\mathrm{C}$$, its volume decreases to $$2.57\ \mathrm{L}. $$What was the initial temperature in Kelvin? (Assume constant pressure.)

Accepted Answer

$$297\ \mathrm{K}$$

Question 4

Which of the following statements about the behavior of gases is NOT predicted by the kinetic molecular theory?

Accepted Answer

Gas particles attract each other strongly.

Question 5

A mixture of helium, neon, and argon has a total pressure of $$558\ \mathrm{mm\ Hg}. If $$the partial pressure of helium is $$341\ \mathrm{mm\ Hg}$$ and the partial pressure of neon is $$112\ \mathrm{mm\ Hg}$$, what is the partial pressure of argon?

Accepted Answer

$$105\ \mathrm{mm\ Hg}$$

Question 6

Which of the following is the correct expression for the combined gas law?

Accepted Answer

$$\dfrac{P_1V_1}{T_1$} = \dfrac{P_2V_2}{T_2$}$$

Question 7

A 4.8-L sample of helium gas contains $$0.22\ \mathrm{mol} of $$helium. How many additional moles of helium must be added to obtain a volume of $$6.4\ \mathrm{L} at $$constant temperature and pressure?

Accepted Answer

$$0.13\ \mathrm{mol}$$

Question 8

Which of the following best describes why a hot air balloon rises?

Accepted Answer

The heated air inside the balloon has a lower density than the cooler air outside.

Question 9

Convert $$0.311\ \mathrm{atm} to $$millimeters of mercury (mm Hg).

Accepted Answer

$$236\ \mathrm{mm\ Hg}$$

Question 10

A sample of gas has a mass of $$0.136\ \mathrm{g}$$, a volume of $$0.112\ \mathrm{L}$$, a temperature of $$298\ \mathrm{K}$$, and a pressure of $$1.06\ \mathrm{atm}. $$What is the molar mass of the gas? (Use $$R = 0.0821\ \mathrm{L\ atm\ $$mol^{-1}$$\ K$$^{-1}$$})$$

Accepted Answer

$$31.5\ \mathrm{g/mol}$$

Question 11

Which of the following is NOT a property of gases explained by the kinetic molecular theory?

Accepted Answer

Gases have high densities compared to solids.

Question 12

A diver breathes a heliox mixture containing $$2.0\%$$ oxygen at a depth of $$90\ \mathrm{m}$$, where the total pressure is $$10.0\ \mathrm{atm}. $$What is the partial pressure of oxygen?

Accepted Answer

$$2.0\ \mathrm{atm}$$

Question 13

Which of the following is the correct value for the molar volume of an ideal gas at standard temperature and pressure (STP)?

Accepted Answer

$$22.4\ \mathrm{L}$$

Question 14

Which of the following is the correct equation for Boyle’s Law?

Accepted Answer

$$P_1V_1 = P_2V_2$$

Question 15

A sample of gas has an initial volume of $$158\ \mathrm{mL} at a $$pressure of $$735\ \mathrm{mm\ Hg}$$ and a temperature of $$34\ ^\circ\mathrm{C}. If $$the gas is compressed to $$108\ \mathrm{mL}$$ and heated to $$85\ ^\circ\mathrm{C}$$, what is its final pressure in mm Hg? (Use the combined gas law.)

Accepted Answer

$$1100\ \mathrm{mm\ Hg}$$

Question 16

Which of the following is a real-world consequence of the pressure difference experienced when climbing a mountain or flying in an airplane?

Accepted Answer

The external pressure drops, causing your eardrum to bulge outward and possibly causing pain.

Question 17

Which of the following is the correct relationship for Avogadro’s Law?

Accepted Answer

$$V \propto n$$

Question 18

Which of the following pollutants is primarily responsible for the orange-brown haze seen over polluted cities and is an eye and lung irritant?

Accepted Answer

Nitrogen dioxide

Chapter 11: Gases – Introductory Chemistry Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard