1. Gas Laws Practice Problems 1) Work out each problem on scratch paper. 2) Click ANSWER to check your answer. 3) Click NEXT to go on to the next problem. P 1 V 1 T 2 = P 2 V 2 T 1 CLICK TO START

2. 1 2 3 4 5 6 7 8 9 10 Helium occupies 3.8 L at -45°C. What volume will it occupy at 45°C? ANSWER QUESTION #1

3. 1 2 3 4 5 6 7 8 9 10 ANSWER #1 V 1 = 3.8 L T 1 = -45°C = 228 K V 2 = ? T 2 = 45°C = 318 K NEXT CHARLES’ LAW P 1 V 1 T 2 = P 2 V 2 T 1 V 2 = 5.3 L BACK TO PROBLEM

4. 1 2 3 4 5 6 7 8 9 10 Ammonia gas occupies a volume of 450. mL at 720. mm Hg. What volume will it occupy at standard pressure? ANSWER QUESTION #2

5. 1 2 3 4 5 6 7 8 9 10 ANSWER #2 V 1 = 450. mL P 1 = 720. mm Hg V 2 = ? P 2 = 760. mm Hg NEXT BOYLE’S LAW P 1 V 1 T 2 = P 2 V 2 T 1 V 2 = 426 mL BACK TO PROBLEM

6. 1 2 3 4 5 6 7 8 9 10 A gas at STP is cooled to -185°C. What pressure in atmospheres will it have at this temperature (volume remains constant)? ANSWER QUESTION #3

7. 1 2 3 4 5 6 7 8 9 10 ANSWER #3 P 1 = 1 atm T 1 = 273 K P 2 = ? T 2 = -185°C = 88 K NEXT GAY-LUSSAC’S LAW P 1 V 1 T 2 = P 2 V 2 T 1 P 2 = 0.32 atm BACK TO PROBLEM

8. 1 2 3 4 5 6 7 8 9 10 A gas occupies 1.5 L at 850 mm Hg and 15°C. At what pressure will this gas occupy 2.5 L at 30.0°C? ANSWER QUESTION #4

9. 1 2 3 4 5 6 7 8 9 10 ANSWER #4 V 1 = 1.5 L P 1 = 850 mm Hg T 1 = 15°C = 288 K P 2 = ? V 2 = 2.5 L T 2 = 30.0°C = 303 K NEXT COMBINED GAS LAW P 1 V 1 T 2 = P 2 V 2 T 1 P 2 = 540 mm Hg BACK TO PROBLEM

10. 1 2 3 4 5 6 7 8 9 10 Chlorine gas has a pressure of 1.05 atm at 25°C. What pressure will it exert at 75°C? ANSWER QUESTION #5

11. 1 2 3 4 5 6 7 8 9 10 ANSWER #5 P 1 = 1.05 atm T 1 = 25°C = 298 K P 2 = ? T 2 = 75°C = 348 K NEXT GAY-LUSSAC’S LAW P 1 V 1 T 2 = P 2 V 2 T 1 P 2 = 1.23 atm BACK TO PROBLEM

12. 1 2 3 4 5 6 7 8 9 10 A gas occupies 256 mL at 720 torr and 25°C. What will its volume be at STP? ANSWER QUESTION #6

13. 1 2 3 4 5 6 7 8 9 10 ANSWER #6 V 1 = 256 mL P 1 = 720 torr T 1 = 25°C = 298 K V 2 = ? P 2 = 760. torr T 2 = 273 K NEXT COMBINED GAS LAW P 1 V 1 T 2 = P 2 V 2 T 1 V 2 = 220 mL BACK TO PROBLEM

14. 1 2 3 4 5 6 7 8 9 10 At 27°C, fluorine occupies a volume of 0.500 dm 3. To what temperature in degrees Celsius should it be lowered to bring the volume to 200. mL? ANSWER QUESTION #7

15. 1 2 3 4 5 6 7 8 9 10 ANSWER #7 T 1 = 27ºC = 300. K V 1 = 0.500 dm 3 T 2 = ?°C V 2 = 200. mL = 0.200 dm 3 NEXT CHARLES’ LAW P 1 V 1 T 2 = P 2 V 2 T 1 T 2 = -153°C (120 K) BACK TO PROBLEM

16. 1 2 3 4 5 6 7 8 9 10 A gas occupies 125 mL at 125 kPa. After being heated to 75°C and depressurized to 100.0 kPa, it occupies 0.100 L. What was the original temperature of the gas? ANSWER QUESTION #8

17. 1 2 3 4 5 6 7 8 9 10 ANSWER #8 V 1 = 125 mL P 1 = 125 kPa T 2 = 75°C = 348 K P 2 = 100.0 kPa V 2 = 0.100 L = 100. mL T 1 = ? NEXT COMBINED GAS LAW P 1 V 1 T 2 = P 2 V 2 T 1 T 1 = 544 K (271°C) BACK TO PROBLEM

18. 1 2 3 4 5 6 7 8 9 10 ANSWER QUESTION #9 A 3.2-L sample of gas has a pressure of 102 kPa. If the volume is reduced to 0.65 L, what pressure will the gas exert?

19. 1 2 3 4 5 6 7 8 9 10 ANSWER #9 V 1 = 3.2 L P 1 = 102 kPa V 2 = 0.65 L P 2 = ? NEXT BOYLE’S LAW P 1 V 1 T 2 = P 2 V 2 T 1 P 2 = 502 kPa BACK TO PROBLEM

20. 1 2 3 4 5 6 7 8 9 10 A gas at 2.5 atm and 25°C expands to 750 mL after being cooled to 0.0°C and depressurized to 122 kPa. What was the original volume of the gas? ANSWER QUESTION #10

21. 1 2 3 4 5 6 7 8 9 10 ANSWER #10 P 1 = 2.5 atm T 1 = 25°C = 298 K V 2 = 750 mL T 2 = 0.0°C = 273 K P 2 = 122 kPa = 1.20 atm V 1 = ? EXIT COMBINED GAS LAW P 1 V 1 T 2 = P 2 V 2 T 1 V 1 = 390 mL BACK TO PROBLEM

22. Ideal Gas Law & Gas Stoichiometry 1) Work out each problem on scratch paper. 2) Click ANSWER to check your answer. 3) Click NEXT to go on to the next problem. PV = nRT R = 0.0821 L  atm/mol  K = 8.315 dm 3  kPa/mol  K CLICK TO START

23. 1 2 3 4 5 6 7 8 9 10 Tire of car contains nitrogen, oxygen, carbon dioxide and argon. The total pressure of the tire is 93.6 kPa. The partial pressures of nitrogen, oxygen & carbon dioxide are 15.4 kPa, 90 mmHg and.356 atm. resp. What is the partial pressure exerted by argon? Given P- total = 93.6KPa P N = 15.4 kPa P O = 90 mmHg P CO2 =.356 atm Solve : P total = P 1 + P 2 + P 3 + P 4

24. 1 2 3 4 5 6 7 8 9 10 How many grams of CO 2 are produced from 75 L of CO at 35°C and 96.2 kPa? 2CO + O 2  2CO 2 ANSWER QUESTION #1

25. 1 2 3 4 5 6 7 8 9 10 Find the new molar volume: n = 1 mol V = ? P = 96.2 kPa T = 35°C = 308 K R = 8.315 dm 3  kPa/mol  K CONTINUE... PV = nRT V = 26.6 L/mol BACK TO PROBLEM ANSWER #1

26. 1 2 3 4 5 6 7 8 9 10 NEXTBACK TO PROBLEM ANSWER #1 (con’t) 75 L CO 1 mol CO 26.6 L CO = 120 g CO 2 2 mol CO 2 2 mol CO 44.01 g CO 2 1 mol CO 2 2CO + O 2  2CO 2 75 L? g

27. 1 2 3 4 5 6 7 8 9 10 How many moles of oxygen will occupy a volume of 2.5 L at 1.2 atm and 25°C? ANSWER QUESTION #2

28. 1 2 3 4 5 6 7 8 9 10 n = ? V = 2.5 L P = 1.2 atm T = 25°C = 298 K R = 0.0821 L  atm/mol  K NEXT PV = nRT n = 0.12 mol BACK TO PROBLEM ANSWER #2

29. 1 2 3 4 5 6 7 8 9 10 What volume will 56.0 grams of nitrogen (N 2 ) occupy at 96.0 kPa and 21°C? ANSWER QUESTION #3

30. 1 2 3 4 5 6 7 8 9 10 V = ? n = 56.0 g = 2.00 mol P = 96.0 kPa T = 21°C = 294 K R = 8.315 dm 3  kPa/mol  K NEXT PV = nRT V = 50.9 dm 3 BACK TO PROBLEM ANSWER #3

31. 1 2 3 4 5 6 7 8 9 10 What volume of NH 3 at STP is produced if 25.0 g of N 2 is reacted with excess H 2 ? N 2 + 3H 2  2NH 3 ANSWER QUESTION #4

32. 1 2 3 4 5 6 7 8 9 10 25.0 g N 2 NEXTBACK TO PROBLEM ANSWER #4 1 mol N 2 28.02 g N 2 = 40.0 L NH 3 N 2 + 3H 2  NH 3 2 mol NH 3 1 mol N 2 22.4 L NH 3 1 mol NH 3 25.0 g? L

33. 1 2 3 4 5 6 7 8 9 10 What volume of hydrogen is produced from 25.0 g of water at 27°C and 1.16 atm? 2H 2 O  2H 2 + O 2 ANSWER QUESTION #5

34. 1 2 3 4 5 6 7 8 9 10 Find the new molar volume: n = 1 mol V = ? P = 1.16 atm T = 27°C = 300. K R = 0.0821 L  atm/mol  K CONTINUE... PV = nRT V = 21.2 L/mol BACK TO PROBLEM ANSWER #5

35. 1 2 3 4 5 6 7 8 9 10 NEXTBACK TO PROBLEM ANSWER #5 (con’t) 25.0 g H 2 O 1 mol H 2 O 18.02 g H 2 O = 29.4 L H 2 2 mol H 2 2 mol H 2 O 21.2 L H 2 1 mol H 2 2H 2 O  2H 2 + O 2 25.0 g? L

36. 1 2 3 4 5 6 7 8 9 10 How many atmospheres of pressure will be exerted by 25 g of CO 2 at 25°C and 0.500 L? ANSWER QUESTION #6

37. 1 2 3 4 5 6 7 8 9 10 P = ? n = 25 g = 0.57 mol T = 25°C = 298 K V = 0.500 L R = 0.0821 L  atm/mol  K NEXT PV = nRT P = 28 atm BACK TO PROBLEM ANSWER #6

38. 1 2 3 4 5 6 7 8 9 10 How many grams of CaCO 3 are required to produce 45.0 L of CO 2 at 25°C and 2.3 atm? CaCO 3 + 2HCl  CO 2 + H 2 O + CaCl 2 ANSWER QUESTION #7

39. 1 2 3 4 5 6 7 8 9 10 Find the new molar volume: n = 1 mol V = ? P = 2.3 atm T = 25°C = 298 K R = 0.0821 L  atm/mol  K CONTINUE... PV = nRT V = 11 L/mol BACK TO PROBLEM ANSWER #7

40. 1 2 3 4 5 6 7 8 9 10 NEXTBACK TO PROBLEM ANSWER #7 45.0dm 3 CO 2 1 mol CO 2 11 dm 3 CO 2 = 410 g CaCO 3 CaCO 3 + 2HCl  CO 2 + H 2 O + CaCl 2 1 mol CaCO 3 1 mol CO 2 100.09 g CaCO 3 1 mol CaCO 3 ? g45.0 dm 3

41. 1 2 3 4 5 6 7 8 9 10 Find the number of grams of CO 2 that exert a pressure of 785 torr at 32.5 L and 32°C. ANSWER QUESTION #8

42. 1 2 3 4 5 6 7 8 9 10 n = ? P = 785 torr = 1.03 atm V = 32.5 L T = 32°C = 305 K R = 0.0821 L  atm/mol  K NEXT PV = nRT n = 1.34 mol  59.0 g CO 2 BACK TO PROBLEM ANSWER #8