Boyle s Law Practice Problems Name:

Transcription

1 Boyle s Law Practice Problems Name: 1. If a gas at 25.0 C occupies 3.60 L at a pressure of 1.00 atm, what will be its volume at a pressure of 2.50 atm? ml of a gas is collected at mm Hg. What will the pressure be with an decrease of volume of 25mL? 3. Convert ml at mm of Hg to its new volume at standard pressure L of gas at a pressure of 18.0 mm of Hg has an increase of pressure to 1 atm. What is the new volume? 5. A gas occupies 4.31 L at a pressure of atm. Determine the volume if the pressure is increased to 1.25 atm.

2 ml of a gas are under a pressure of torr. What would the volume of the gas be at a pressure of torr? L of a gas are under a pressure of 6.00 atm. What is the pressure of gas at 12L? 8. A gas occupies 25.3 ml at a pressure of mm Hg. Determine the volume if the pressure is reduced to atm. 9. A 1.5 L flask is filled with nitrogen at a pressure of 12 atmospheres. What size flask would be required to hold this gas at a pressure of 2.0 atm? 10. You are now wearing scuba gear and swimming under water at a depth of 30.0 m. You are breathing air at 3.00 atm and your lung volume is 10.0 L. Your scuba gauge indicates that your air supply is low so, to conserve air, you make a terrible and fatal mistake: you hold your breath while you surface. What happens to your lungs? Why?

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4 Charles Law Assignment Name: cm 3 of chlorine at 25 C will occupy what volume at -25 C while the pressure remains constant? 2. A sample of nitrogen now occupies a volume of 250 ml at 25 C. What volume did it occupy at 95 C? 3. Oxygen gas is at a temperature of 40 C when it occupies a volume of 2.30 L. To what temperature should it be raised to occupy a volume of 6.50 L? 4. Hydrogen gas was cooled from 150 C to 50 C. Its new volume is 75.0 ml. What was its original volume? 5. Fluorine gas at 300 K occupies a volume of 500 ml. To what temperature should it be lowered to bring the volume to 300 ml?

5 6. A sample of argon gas is cooled and its volume went from 380 ml to 250 ml. If its final temperature was 55 C, what was its original temperature? 7. A container holds 50.0 ml of nitrogen at 25 C and at a constant pressure of 736 mm Hg. What will be its volume if the temperature increases by 35 C? 8. On hot days, you may have noticed that potato chip bags seem to expand. If a 250 ml bag at a temperature of 19 C is left inside a car (with windows sealed on a hot summer day) when the temperature rises to 60 C, what will be new volume of the bag? 9. A plastic pop bottle is flexible enough that the volume of the bottle can change even without opening it. If you have an empty 2 L pop bottle at a room temperature of 25 C, what will the new volume be if you put it in the freezer at -4 C? 10. A homemade thermometer is produced so that a piston goes up and down as the temperature changes. It is calibrated so that at 100 C, the piston is at the 30 L position. If the piston indicates 20 L, should you wear a jacket or a bathing suit before going out? Explain your answer using your calculations.

6 Combined Gas Law Practice Problems Name: 1. A gas is at 135 C and 455 mm Hg in a 2.00 L container. It is cooled down to a temperature of 25 C. If it is kept in the same container, what is its new pressure? 2. A gas has a volume of 39 L at STP. What will its volume be at 4 atm and 25 C? 3. A gas, now contained at STP, has a volume of 500 ml. The initial pressure was 0.96 atm at 20 C. What was the initial volume? 4. A balloon is filled up with air to a volume of 1.15 L at K. What does the volume change to if the balloon is taken outdoors where the temperature is K and the pressure is half of what it was indoors? 5. A ml gas sample gas sample at STP is compressed to a volume of ml, and the temperature is increased to C. What is the new pressure of the gas in kpa?

7 6. A balloon of air now occupies 10.0 L at 25.0 C and 1.00 atm. What temperature was it initially, if it occupied 9.4 L and was in a freezer with a pressure of atm? L of a gas is found to exert 97.3 kpa at 25.2 C. If the volume is changed to 12.5 L, what would be the required temperature to change the pressure to standard pressure? 8. A cylinder is fitted with a moveable piston. A gas in the cylinder is heated up. If the pressure only increases slightly, what will happen to the volume of the cylinder? Why? 9. You go on a road trip to escape the cold winter days of Canada to the warm beaches of Florida. Since it is a long drive and you are leaving early in the morning, you make sure to check the tire pressure and make sure it is at the recommended level. At lunchtime, you stop for gas and decide to check your car's tire pressure again. You also notice that the tires seem to be a little bit larger than when you left. The driver's manual suggests a pressure between 205 and 220 kpa. Knowing that the tires heat up while driving; do you expect your reading to be high, low or the same as the recommended tire pressure? Why? Since you plan on staying in Florida a while to see the sights, you think it would be best to adjust your tire pressure? What adjustments should be made to your tires? Should you make these adjustments as soon as you arrive, or the following day?

8 Gay-Lussac s Law Practice Problems Name: 1. A gas container is initially at 47 mm Hg and 77 K. What will the pressure be when the container warms up to room temperature of 25 C? 2. A gas thermometer measures temperature by measuring the pressure of a gas inside the fixed volume container. A thermometer reads a pressure of 248 torr at 0.0 C. What is the temperature when the thermometer reads a pressure of 345 torr? 3. Calculate the final pressure inside a scuba tank after it cools from 1000 C to 25 C. The initial pressure in the tank is atm. 4. A gas is collected at 22 C and 745 mm Hg. When the temperature is changed to 0.0 C, what is the resulting pressure? 5. Use Gay-Lussac's law to explain what is wrong with the following statement: "I brought a fully inflated beach ball outside to play volleyball in the snow with my friends, but it exploded before we could start."

9 6. The gas pressure in an aerosol can is kpa at 25.0 C, what would the pressure be inside the can at C? 7. The temperature of a gas is 6.0 C and 65.3 mbar, what is the pressure at 4.0 C? 8. A tank for compressed gas has a maximum safe pressure limit of 825 kpa. The pressure gauge reads 388 kpa when the temperature is 24.0 C. What is the highest temperature the tank can withstand safely? 9. If a helium-filled balloon is at STP. What was its initial temperature if its pressure was 1.62 atm? 10. What information is missing from the following question? "A small ball is inflated to 100 kpa of pressure. What is the final pressure if the temperature increases by 20 C? "

10 Gas Law Practice Problems Name: 1 atm = 760 mm Hg = kpa = 760 torr STP: 0 C & 1 atm P1V1 = P2V2 P1T2 = P2T1 V1T2= V2T1 V1 P1T2= V2 P2T1 1. Acetylene gas, C2H2 is used for welding. A 5L supply of acetylene being stored at -23 C, exerts a pressure of 5 atm. At what temperature would the same number of moles of acetylene, moved to a 10L container, produce a pressure of 2 atm? 2. A 400 ml sample of nitrogen in a sealed, inflexible container has a pressure of 1200 torr at a temperature of 250 K. It is known that the container will rupture at a pressure of 1800 torr. At what temperature will the container rupture? 3. A chemist produces 460 ml of oxygen gas at - 43 C and constant pressure. To what Celsius temperature must the oxygen be warmed in order for it to have a volume of 600 ml? 4. If I have 5.6 liters of gas in a piston at a pressure of 1.5 atm and compress the gas until its volume is 4800 ml, what will the new pressure inside the piston be?

11 5. A balloon has an internal pressure of 1.05 atm and a volume of 5.0 L. If the temperature where the balloon is released is 20 C, what will happen to the volume when the balloon rises to an altitude where the pressure is kpa and the temperature is 15 C? 6. A sample of neon is at 89 C and 123 kpa. If the pressure changes to mm Hg and the volume remains constant, find the new temperature. 7. The volume of the lungs is measured by the volume of air inhaled or exhaled. If the volume of the lungs is L during exhalation and the pressure is KPa, and the pressure during inhalation is KPa, what is the volume of the lungs during inhalation? 8. If a scuba tank that has a capacity of cm 3 is filled with air to 4.93atm, what will be the volume of the air at KPa? 9. People who are angry sometimes say that they feel as if they ll explode. If a calm person with a lung capacity of 3.5 liters and a body temperature of 36 0 C gets angry, what will the volume of the person s lungs be if their temperature rises to 39 0 C. Based on this, do you think it s likely they will explode? 10. A gas takes up 25.2L at 25 o C. At 25 o C, the gas can also take up 12.2L at 1500 torr. What was the pressure, in atm, of the original sample?

12 11. A gas at STP is cooled to -185 C. What pressure will it have cooled to this temperature? 12. A Los Angeles class nuclear submarine has an internal volume of eleven million liters at a pressure of atm. If a crewman were to open one of the hatches to the outside ocean while it was underwater (pressure = atm), what would the new volume of the air inside the submarine? 13. A commercial airliner has an internal pressure of 1.00 atm and temperature of 25 C at takeoff. If the temperature of the airliner drops to 17 C during the flight, what is the new cabin pressure? 14. I have 130 liters of gas in a piston at a temperature of 250 C. If I cool the gas until the volume decreases to 85 liters, what will temperature of the gas be?

13 Ideal Gas Law Practice Problems Name: R = J/mol K = L kpa/k mol = L atm/k mol = 62.4 L mm Hg/K mol 1. At what temperature will moles of neon gas occupy L at 1.95 atm? 2. A sample of argon gas at STP occupies 56.2 L. Determine the number of moles of argon mol of a gas is compressed in a 25 L storage tank with a temperature of 21 C. What pressure must be applied to the tank for that gas to sustain these conditions? 4. What volume will 45 grams of hydrogen gas occupy at 1.05 atm and 25 C? 5. At what temperature will 5.00 g of Cl2 exert a pressure of 900 mm Hg at a volume of ml?

14 6. A g sample of a gas is at torr, K and occupies 29.1 L. What is the chemical formula for this gas? (hint: find the molar mass) 7. A 28.8 g piece of dry ice (solid carbon dioxide) is allowed to sublime (convert directly from a solid to a gas) into a large balloon. Assuming that all of the carbon dioxide ends up in the balloon, what will the volume of the balloon be at a temperature of 22 C and a pressure of 742 mm Hg? 8. What pressure is exerted by 0.325mol of hydrogen gas in a 4.08L container at 35 C? 9. Ammonium nitrate decomposes explosively upon heating according to the following equation: 2NH4NO3(s) 2NH3 (g) + CO2 (g) + H2O (g) Calculate the total volume of gas produced at 125 C and 748 mm Hg when 1.55 kg of ammonium nitrate completely decomposes. 10. Aerosol cans carry clear warnings against incineration because high pressures can develop at high temperature. Using the ideal gas law, explain the basis for this warning.

15 Dalton s Law of Partial Pressure Name: 1. Oxygen gas from the decompostition of potassium chlorate, KClO3, as collected over water. The pressure and the temperature during the experiment was 731 torr and 20 C. What was the partial pressure of oxygen collected? 2. Nitrogen is collected over water at 40 C. What is the partial pressure of nitrogen if the total pressure is 99.4 kpa? 3. A sample of nitrogen gas is collected over water at a temperature of 25 C. What is the pressure of nitrogen gas if the pressure is 785 mm Hg? 4. A sample of hydrogen is collected by displacing a sample of water with a temperature of 35 C. The mixture has a total pressure of 114 kpa. What is the partial pressure of the dry hydrogen?

16 5. What is the pressure of "wet" oxygen if 0.8 mol of dry oxygen at kpa is collected? The atmospheric pressure in the lab that day is 99.4 kpa. The oxygen is to be collected over water at a temperature of 15.0 C. 6. Consider a mixture of two gases, A and B, confined to a closed container. A quantity of a third gas, C, is added to the same container at the same temperature. How does the addition of gas C affect the following: a. the partial pressure of gas A b. the total pressure in the container Vapour Pressures of Water Temperature ( C) Pressure of Water (kpa)