Practice Problems. Unit 11 - Gas Laws. CRHS Academic Chemistry. Due Date Assignment On-Time (100) Late (70)

Transcription

1 Name Period CRHS Academic Chemistry Unit 11 - Gas Laws Practice Problems Due Date Assignment On-Time (100) Late (70) Warm-Up EC Notes, Homework, Exam Reviews and Their KEYS located on CRHS Academic Chemistry Website:

2 Page 2 of 12 Unit 11 HW Dalton s Law P Total = P 1 + P 2 + P 3 Ideal Gas Law PV = nrt Combined Gas Law P 1 V 1 T 1 = P 2V 2 T 2 Boyle s Law P 1 V 1 = P 2 V 2 Charles s Law V 1 T 1 = V 2 T 2 Gay-Lussac s Law P 1 T 1 = P 2 T 2 STP Temperature: 273K = 0 C Pressure: kpa = 1.0 atm = 760 mmhg K = C + 273

3 Unit 11 HW Page 3 of 12 WARM-UPS Day 1 Day 2 Day 3 Day 4 Day 5 Day 6

4 Page 4 of 12 Unit 11 HW 11.1 GASES AND THE FOUR VARIABLES For numbers 1-3, CIRCLE the italicized term that best completes the sentence. 1. During gas particle collision, kinetic energy ( increases / decreases / stays the same). 2. As temperature increases, kinetic energy ( increases / decreases / stays the same). 3. As the speed of gas molecules increases, kinetic energy ( increases / decreases / stays the same). 4. Why are gases able to be compressed? 5. The SI unit for volume is, pressure is, and temperature is. 6. Convert the following. a. 24 C K b. 58 C K c. 54 K C d. 324 K C 7. Convert the following. a atm mmhg b kpa atm c atm kpa d kpa mmhg 8. What is absolute zero?

5 Unit 11 HW Page 5 of You have a sample of a gas in a sealed, rigid (cannot be stretched or enlarged) cylinder. If you INCREASE the temperature of the cylinder, what happens to a. the kinetic energy of the gas molecules. b. The pressure exerted by the gas molecules on the walls of the container. c. The speed of the gas molecules. d. The number of collisions of gas molecules with other gas molecules. 10. What is the total pressure (in mmhg) exerted by a sample of gases containing 319 mmhg H 2, 201 mmhg N 2, and 0.6 mmhg O 2? 11. If the total pressure of a mixture of O 2, N 2, and H 2 is 902 mmhg, what is the pressure of O 2 if there pressure of N 2 is 355 mmhg N 2 and H 2 is 255 mmhg?

6 Page 6 of 12 Unit 11 HW 11.2 IDEAL GAS LAW 1. Determine the temperature (in C ) of 2.49 moles of gas contained in a 1.00 L vessel at a pressure of 143 kpa. 2. What is the pressure (in kpa) of a mol sample of helium gas at 20.0 C if its volume is L? 3. Calculate the number of moles of gas that occupy a 3.45 L container at a pressure of 150 kpa and a temperature of 45.6 C. 4. If mol of methane gas (CH 4) is introduced into a 2.00 L container at 35.0 C, what is the pressure (atm) in the container?

7 Unit 11 HW Page 7 of A 2.00 L flask is filled with propane gas (C 3H 8) at kpa and 15.0 C. What is the mass (in grams) of the propane in the flask? (Hint: Convert moles to grams!) 6. Determine the pressure inside a television picture tube with a volume of 3.50 L that contains 2.00 x 10 5 grams of nitrogen gas at 22.0 C. (Hint: Convert grams to moles! 7. How many grams of oxygen gas must be present in a 2.00 L container at 35 C if the pressure is 212 kpa?

8 Page 8 of 12 Unit 11 HW 11.3 COMBINED GAS LAW For Questions 1-4, circle the correct answer 1. Assuming volume and temperature are held constant in a sealed container, what happens to pressure when more molecules of gas are injected? A Decreases B. Increases C. Stays the Same D. Cannot Determine 2. When the volume of a container is increased, the pressure inside the cylinder. A Decreases B. Increases C. Stays the Same D. Cannot Determine 3. As a gas heats up the average kinetic energy of its molecules will. A Decreases B. Increases C. Stays the Same D. Cannot Determine 4. Assuming pressure and temperature are held constant in a balloon, what happens to volume as gas molecules are removed? A Decreases B. Increases C. Stays the Same D. Cannot Determine 5. A helium filled balloon at sea level has a volume of 2.10 L at atm and 36 C. If it is released and rises to an elevation at which the pressure is atm and the temperature is 28 C, what will be the new volume of the balloon? 6. At 20.0 C and 1.00 atm pressure, a sample of gas occupies 0.03 L. If the temperature is increased to 30.0 C and the entire sample is transferred to a 0.02 L container, what will be the gas pressure inside the container?

9 Unit 11 HW Page 9 of A sample of air in a syringe exerts a pressure of 1.02 atm at a temperature of 22.0 C. The syringe is then placed in a boiling water bath at C. The pressure of the air is increased to 1.23 atm by pushing the plunger in, which reduces the volume to L. What was the original volume of air? 8. An unopened cold 2.00 L soda bottle contains 46.0 ml of gas confined at a pressure of 1.30 atm at a temperature of 5.0 C. If the bottle is dropped into a lake and sinks to a depth at which the pressure is 2.85 atm and temperature is 2.09 C, what will the volume of the gas in the bottle be? (NOTE: Be sure to convert ml to L) 9. A sample of unknown pressure occupies L at a temperature of 298 K. The same sample of gas is then tested under known conditions and has a pressure of 32.6 kpa and occupies L at 303 K. What was the original pressure of the gas? 10. A gas at 110 kpa and 30.0 C fills a flexible container with an initial volume of 2.00 L. If the temperature is raised to 80.0 C and the pressure is increased to 440 kpa, what is the new volume?

10 Page 10 of 12 Unit 11 HW 11.4 INDIVIDUAL GAS LAWS Read each question. Circle the gas law that applies to the problem. Then, solve for the missing variable. 1. If a basketball has a volume 2.50 L and a temperature of 25 C, what will its new volume be if it is left in the cold at temperature of 10.0 C? Assume that pressure remains constant. ( Boyle s / Charles s / Gay Lussac s ) 2. If a balloon has a pressure of 1.30 atm and a temperature of C. If volume remains constant, and its temperature is raised to 215 C, what will the new pressure be? ( Boyle s / Charles s / Gay- Lussac s ) 3. If a balloon has a volume of 3.00 L and a pressure of mmhg, what will its pressure be if its volume decreases to 2.00 L? Assume that temperature remains constant. ( Boyle s / Charles s / Gay-Lussac s ) 4. If a ball has an initial temperature of 315 K, what will its final temperature be if the pressure is changed from 1.20 atm to 13.2 atm? Assume that volume remains constant. ( Boyle s / Charles s / Gay Lussac s )

11 Unit 11 HW Page 11 of A ball has a volume of 3.50 L and a pressure of kpa. If temperature remains constants, how large will the volume be if we increase the pressure to kpa? ( Boyle s / Charles s / Gay Lussac s ) 6. If a balloon has a volume of 3.20 L at 273 K, what will its volume be at 473 K? Pressure is held constant. ( Boyle s / Charles s / Gay Lussac s )

12 Page 12 of 12 Unit 11 HW