Question 1

According to the kinetic molecular theory, which of the following statements best explains why gases are compressible?

Accepted Answer

Gas particles are in constant, random motion and occupy a lot of space compared to their size.

Question 2

A sample of gas has a pressure of 0.311 atm. What is this pressure in millimeters of mercury (mm Hg)? Use the conversion $$1\ 	ext{atm} = 760\ 	ext{mm Hg}.$$

Accepted Answer

$$236\ 	ext{mm Hg}$$

Question 3

Which of the following best describes the relationship between the volume and pressure of a gas at constant temperature and amount, according to Boyle’s Law?

Accepted Answer

The volume of a gas is inversely proportional to its pressure.

Question 4

A cylinder contains 4.0 atm of gas at a volume of 6.0 L. If the pressure is decreased to 1.0 atm at constant temperature, what is the new volume?

Accepted Answer

$$24\ 	ext{L}$$

Question 5

A sample of gas has a volume of 2.80 L at an unknown temperature. When cooled to $$0\ ^\circ	ext{C}$$, its volume decreases to 2.57 L. What was the initial temperature in Kelvin?

Accepted Answer

$$298\ 	ext{K}$$

Question 6

Which of the following is the correct form of the combined gas law?

Accepted Answer

$$\frac{P_1$ V_1$}{T_1$} = \frac{P_2$ V_2$}{T_2$}$$

Question 7

A gas sample has an initial volume of 158 mL at 735 mm Hg and $$34\ ^\circ	ext{C}. If $$the gas is compressed to 108 mL and heated to $$85\ ^\circ	ext{C}$$, what is the final pressure in mm Hg?

Accepted Answer

$$1,250\ 	ext{mm Hg}$$

Question 8

According to Avogadro’s Law, what happens to the volume of a gas if the number of moles is doubled at constant temperature and pressure?

Accepted Answer

The volume doubles.

Question 9

Calculate the volume occupied by 0.845 mol of nitrogen gas at a pressure of 1.37 atm and a temperature of 315 K. Use $$R = 0.0821\ 	ext{L} \cdot 	ext{atm} / (	ext{mol} \cdot 	ext{K}).$$

Accepted Answer

$$16.0\ 	ext{L}$$

Question 10

A sample of gas has a mass of 0.136 g, a volume of 0.112 L, a temperature of 298 K, and a pressure of 1.06 atm. What is the molar mass of the gas?

Accepted Answer

$$28.0\ 	ext{g/mol}$$

Question 11

Which of the following conditions would cause a real gas to deviate most from ideal behavior?

Accepted Answer

Low temperature and high pressure

Question 12

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

Accepted Answer

$$105\ 	ext{mm Hg}$$

Question 13

A diver breathes a heliox mixture containing 2.0% oxygen at a depth where the total pressure is 10.0 atm. What is the partial pressure of oxygen?

Accepted Answer

$$0.20\ 	ext{atm}$$

Question 14

Hydrogen gas is collected over water at a total pressure of 758 mm Hg and a temperature of $$25\ ^\circ	ext{C}. If $$the vapor pressure of water at this temperature is 23.8 mm Hg, what is the partial pressure of the hydrogen gas?

Accepted Answer

$$734.2\ 	ext{mm Hg}$$

Question 15

How many liters of oxygen gas are produced at STP when 0.879 moles of $$\mathrm{$$CaCO_3$$}$$ decompose according to the reaction $$\mathrm{$$CaCO_3$$(s) \rightarrow CaO(s) + CO_2$(g)}$$?

Accepted Answer

$$19.7\ 	ext{L}$$

Question 16

Which of the following best explains why hot air rises, based on the kinetic molecular theory and gas laws?

Accepted Answer

Hot air is less dense because its particles move faster and occupy a larger volume.

Question 17

A basketball is inflated to a total pressure of 24.2 psi with a volume of 3.2 L at $$25\ ^\circ	ext{C}. $$How many moles of gas are in the basketball? ($$1\ 	ext{atm} = 14.7\ 	ext{psi}$$, $$R = 0.0821\ 	ext{L} \cdot 	ext{atm} / (	ext{mol} \cdot 	ext{K}))$$

Accepted Answer

$$0.22\ 	ext{mol}$$

Question 18

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

Accepted Answer

$$22.4\ 	ext{L}$$

Chapter 11: Gases – Properties, Laws, and Applications

Guida di studio - Domande di pratica

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