REVIEW EXERCISES

General Review

Write a brief and clear answer to each question. Be sure to show your work.

Question 1

1. Suppose that you have a 500 mL sample of liquid water and a 500 mL sample of ice. The ice has a density of 0.92 g/mL. Which has a greater mass? Explain your reasoning.

Question 2

2. Convert 25 °F to kelvins. Show your work.

Question 3

3. Use the kinetic theory of gases to explain why a gas expands when heated and contracts when cooled.

Question 4

4. Suppose that you fill a balloon with 600 mL of air when the temperature is 27 °C. Later in the day, the temperature drops to 21 °C. Determine the new volume of the balloon.

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Question 5

5. A cylinder with a movable piston contains 2.5 L of gas at a pressure of 2 atm. If the volume is decreased to 2.1 L and the temperature stays the same, what is the new pressure of the gas?

Question 6

6. Which graph represents Boyle’s law? Explain your thinking.

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Question 7

7. A propane gas tank contains propane gas at a pressure of 2.00 atm and a temperature of 30 °C. If the temperature is increased to 37 °C, what is the new pressure of the gas?

Question 8

8. Suppose that you fill a balloon with 75 L of air at 28 °C and a pressure of 1 atm. You then take the balloon to the top of a mountain where the pressure is 0.8 atm and the temperature is 18 °C. What is the new volume of the balloon?

Question 9

9. Suppose that you have 22.4 L of nitrogen gas, N2(g), at STP.

  1. What are the temperature and pressure of this sample?

  2. How many molecules of N2 are in the sample?

  3. How many nitrogen atoms are in the sample?

  4. What is the number density, n/V, of nitrogen molecules in the sample?

Question 10

10. Suppose that you have a 750 mL rigid container of hydrogen gas, H2(g), at 250 K and a 750 mL rigid container of nitrogen gas, N2 (g), at 250 K. A pressure gauge on each container shows that they both have the same internal pressure.

  1. What do you know about the number of individual molecules of gas in each container? Explain your reasoning.

  2. Which container would have the greater mass? Explain your reasoning.

Question 11

11. Suppose that you have 77.0 L of hydrogen, H2, gas at a pressure of 3.5 atm and a temperature of 2 °C. How many moles of hydrogen are in this sample?

Question 12

12. Would you feel cooler if the temperature were 28 °C at 100% relative humidity, or 28 °C at 45% relative humidity? Explain your reasoning.

Question 13

13. Name the gas laws. Write the formula associated with each one, and list the factors that must stay constant for each law to apply.