Q: A 2.0 m long steel rail is installed on a bridge at 10°C. If the temperature rises to 40°C, by how much does the rail expand? (Coefficient of linear expansion for steel: $$\alpha = 1.1 \times 10$$^{-5}$$ \, ^\circ \mathrm{C}^{-1})$$

$$\Delta L = (1.1 \times 10$$^{-5}$$)(2.0)(30) = 6.6 \times 10$$^{-4}$$ \, \mathrm{m}$$

Q: A 100 g sample of oxygen gas ($$O_2) is $$placed in a 600 cm$$^3$$ container at 150°C. What is the pressure inside the container? (Molar mass of $$O_2 = 32$ g/mol, R = 8.31$ J/mol·K)

$$p = \frac{nRT}{V} = \frac{3.13 \times 8.31 \times 423}{6.00 \times 10$$^{-4}$$} = 1.83 \times 10^7$ Pa

Q: A 55-m-long steel pipe is heated from 5°C to 155°C. If the coefficient of linear expansion for steel is $$1.1 \times 10$$^{-5}$$ \, ^\circ \mathrm{C}^{-1}$$, by how much does the pipe expand?

$$\Delta L = (1.1 \times 10$$^{-5}$$)(55)(150) = 0.091 m$$

Q: A gas is compressed to half its original volume and three times its original pressure. If the initial temperature is 273 K, what is the final temperature?

$$T_2 = 273$$ \times 3 / 2 = 409$$ K

Q: A constant-volume gas thermometer reads 55.78 kPa at the triple point of water (273.16 K) and 65.12 kPa at an unknown temperature. What is the unknown temperature?

$$T_2 = 273.16$$ \times \frac{65.12}{55.78} = 318.90$$ K

Question 1

Which of the following best describes the microscopic behavior of atoms in a solid?

Accepted Answer

Atoms vibrate around equilibrium positions but are otherwise fixed in a rigid structure.

Question 2

A 2.0 m long steel rail is installed on a bridge at 10°C. If the temperature rises to 40°C, by how much does the rail expand? (Coefficient of linear expansion for steel: $$\alpha = 1.1 	imes 10$$^{-5}$$ \, ^\circ \mathrm{C}^{-1})$$

Accepted Answer

$$\Delta L = (1.1 	imes 10$$^{-5}$$)(2.0)(30) = 6.6 	imes 10$$^{-4}$$ \, \mathrm{m}$$

Question 3

Which of the following statements about the ideal-gas law is correct?

Accepted Answer

It is valid when the density is low and the temperature is well above the condensation point.

Question 4

A sealed container holds 0.5 mol of an ideal gas at 300 K and 2.0 atm. If the temperature is increased to 600 K at constant volume, what is the new pressure?

Accepted Answer

4.0 atm

Question 5

Which equation correctly expresses the relationship between Celsius and Kelvin temperature scales?

Accepted Answer

$$T_K = T_C + 273$$

Question 6

A 100 g sample of oxygen gas ($$O_2) is $$placed in a 600 cm$$^3$$ container at 150°C. What is the pressure inside the container? (Molar mass of $$O_2 = 32$ g/mol, R = 8.31$ J/mol·K)

Accepted Answer

$$p = \frac{nRT}{V} = \frac{3.13 	imes 8.31 	imes 423}{6.00 	imes 10$$^{-4}$$} = 1.83 	imes 10^7$ Pa

Question 7

Which of the following best explains why food takes longer to cook at high altitudes?

Accepted Answer

The boiling point of water is lower at high altitudes, so water boils at a lower temperature.

Question 8

A gas undergoes an isothermal expansion from volume $$V_1 to$$ $$2V_1 at $$temperature $$T. $$What happens to the pressure?

Accepted Answer

It halves.

Question 9

Which of the following is the correct expression for the number density of particles in a system?

Accepted Answer

$$\frac{N}{V}$$

Question 10

A 55-m-long steel pipe is heated from 5°C to 155°C. If the coefficient of linear expansion for steel is $$1.1 	imes 10$$^{-5}$$ \, ^\circ \mathrm{C}^{-1}$$, by how much does the pipe expand?

Accepted Answer

$$\Delta L = (1.1 	imes 10$$^{-5}$$)(55)(150) = 0.091 m$$

Question 11

Which process is represented by a horizontal line on a pV diagram?

Accepted Answer

Isobaric (constant pressure)

Question 12

A gas is compressed to half its original volume and three times its original pressure. If the initial temperature is 273 K, what is the final temperature?

Accepted Answer

$$T_2 = 273$$ 	imes 3 / 2 = 409$$ K

Question 13

Which of the following is true about the triple point of water?

Accepted Answer

It is the only point where solid, liquid, and gas phases of water coexist in equilibrium.

Question 14

Which of the following is the correct form of the ideal-gas law using Boltzmann's constant?

Accepted Answer

$$pV = Nk_B T$$

Question 15

A constant-volume gas thermometer reads 55.78 kPa at the triple point of water (273.16 K) and 65.12 kPa at an unknown temperature. What is the unknown temperature?

Accepted Answer

$$T_2 = 273.16$$ 	imes \frac{65.12}{55.78} = 318.90$$ K

Question 16

Which of the following best describes the behavior of a liquid?

Accepted Answer

Molecules are close together but can move around and slide past each other.

Question 17

If the volume of a gas is doubled at constant pressure, what happens to its temperature?

Accepted Answer

It doubles.

Question 18

Which of the following is the correct definition of molar mass?

Accepted Answer

The mass of 1 mole of a substance.

Question 19

A phase diagram shows the boundaries between different phases of a substance. What does the line between the solid and liquid regions represent?

Accepted Answer

The conditions under which solid and liquid phases coexist in equilibrium.

Chapter 18: A Macroscopic Description of Matter – Study Notes

Study Guide - Practice Questions

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