SAMPLE PROBLEMS ON GASES
1. A 200.0 cm3 gas is collected when the pressure is 1.20 atm. What volume will it occupy at 1.50 atm at constant temperature?
2. A gas collected when the pressure is 900.0 mmHg has a volume of 345 cm3. What volume will it occupy at 750.0 mmHg at the same temperature?
3. In a stormy weather, the atmospheric pressure drops from 760.0 to 700.0 mmHg. At this condition, what is the new volume of a 4.00 liter gas?
4. A gas has a volume of 240.0 cm3 at 70.0 cmHg pressure. Find the pressure in cmHg needed to reduce the volume to half?
5. At 1.25 atm, a certain amount of gas occupies a volume of 3.60 liters. What will be its volume at 0.750 atm? The temperature remains constant.
6. A sample of helium gas exerts a pressure of 800. torr when its volume is 1500. ft3? What pressure will the gas exert if its volume is decreased to 1200. ft3?
7. A fixed amount of gas occupies a volume of 5.00 L at 30.0 oC and 1.00 atm. What will be the new pressure if the volume is 4.00 L at the same temperature?
8. A certain amount of gas at 25.0 oC occupies a container with an adjustable volume. It currently has a volume of 10.5 L, with a pressure of 1.50 atm. What would its volume be if the pressure were adjusted to 1.20 atm?
9. A tank of gas has a volume of 14.92 L and a pressure of 760.0 mmHg. Find the volume of the gas when its pressure is changed to 387.5 mmHg.
10. A 2.50 L sample of a gas is collected at a pressure of 1.25 atm. Calculate the pressure needed to reduce the volume of the gas to 2.00 L.
11. In a cold weather the atmospheric pressure drops from 960. to 540. mmHg. At this condition, what is the new volume of a 3.20 liter gas?
12. What pressure is required to compress 2500. L of hydrogen gas at 1.50 atm pressure into a 1400. L tank at constant temperature?
13. A gas collected when the temperature is 27.0 oC has a volume of 1.50 L. What volume in liters will it occupy at 40.0 oC?
14. A gas has a volume of 180.0 mL when its temperature is 37.0 oC. To what temperature in oC must it be lowered to reduce the volume to one-third?
15. The volume of a gas is 600. mL at 12.0 oC. What volume will it occupy at 273 K?
16. A gas sample occupies a volume of 5.00 L at 30.0 oC and a pressure of 1.50 atm. What will be its temperature if the volume expands to 7.10 L at constant pressure?
17. A certain amount of gas at 25.0 oC occupies a volume of 10.5 L. What would its volume be if gas were heated to 363 K at the same pressure?
18. A balloon has a volume of 25.0 mL on a day when the temperature is 55.0 ºC. If the volume of the gas is raised to 125 mL, what will be the temperature of the gas?
19. At 320. K, a certain quantity of gas occupies a volume of 7.50 L. What will be its volume if the gas is heated to 455 ºC?
20. A gas has a volume of 560. mL when its temperature is 43.7 oC. To what temperature in oC must it be lowered to reduce the volume into half?
21. A 250 mL sample of nitrogen at 127 oC is cooled to 28 oC. What is the resulting volume if the pressure is kept constant?
22. In order to change the volume of a 1200. mL sample of gas at 250. oC to 400. mL, what temperature must be reached if the pressure remains constant?
23. What will be the new volume of a 3.00 L gas at –15.0 oC if its temperature is raised to 30.0 oC? Assume that the pressure is kept constant.
24. What is the volume of 200. mL gas at 130. oC when it is cooled at 150. K?
25. Aerosol cans could be dangerous when they are heated because they can explode. Suppose a can of insecticide with a pressure of 4.00 atm at room temperature (28.0 oC) is thrown into a fire. If the temperature of the gas inside the can reaches 400.0 oC, what will be its pressure?
26. A gas sample has a pressure of 1100.0 torr at 150.0 oC. What is the final pressure of the gas after the temperature dropped to 5.00 oC with constant n and V?
27. A sample of gas at 25.0 oC has a pressure of 1.20 atm. Calculate the final temperature in oC if the pressure is changed to 1.50 atm at constant volume.
28. Determine the new pressure when a constant volume of gas at 10.98 atm is heated from 65.43 ºC to 100. ºC.
29. Determine the temperature when the pressure of a gas at 15.0 atm and 98.0 oC is reduced to 5.35 atm at constant volume.
30. A sample of nitrogen gas has a pressure of 6.58 kPa at 593 K. If the volume does not change, what will the pressure be at 211 K?
31. The pressure in a car tire is 198 kPa at 27.0 oC. After a long drive, the pressure is 225 kPa. What is the temperature of the air in the tire?
32. The gas in a used aerosol can is at pressure of 803 torr at 25.0 oC. If the can is thrown on a fire, what will be the pressure when the temperature reaches 928 K?
33. An aerosol can has a pressure of 1.60 atm at 15.0 oC. What is the final pressure in the aerosol can if it is used in a room where the temperature is 31.0 oC?
34. A fixed amount of gas has a pressure of 1.50 atm at a temperature of 25.0 °C. At what temperature will the pressure be doubled?
35. A 0.65 L container holds a certain gas at 0.25 atm and a temperature of –2.0 °C. The container can only withstand a pressure of 3.0 atm. What is the highest temperature in °C to which the container may be heated?
36. A sample of gas in a container of fixed volume at 28.0 °C has a pressure of 0.75 atm. What temperature in °C is required to have a pressure of 1.75 atm?
37. A gas occupies a volume of 250.0 cm3 at 0 oC and 760.0 mmHg. What volume will it occupy at 100.0 oC and 870 mmHg?
38. A certain gas occupies 500.0 mL at 760.0 torr and 273 K. What volume in cm3 will it occupy at 10.0 atm and 378 K?
39. If a gas sample occupies 6.72 L at STP, what volume will it occupy at 25.0 oC and 800.0 torr?
40. Reduce the volume to standard conditions: 100. cm3 of gas at 23 oC and 720. mmHg pressure.
41. A 1.50 L gas is collected when the temperature is 57.0 oC and the pressure is 600. mmHg. Find the pressure of the gas if the volume increases to 12.5 L at 37.0 oC.
42. If a sample of gas has a volume of 767 dL at –23.0 ºC and 300.5 torr. What would be the volume of the gas at 27.0 ºC and 600.2 torr? The amount of gas is constant.
43. A gas exerts a pressure of 2.40 atm when its volume is 4.00 L at 56.8 ºF. Calculate the pressure exerted by the same gas if the temperature is raised to 287 ºF and the volume is 1.25 L.
44. A gas sample occupies 8.92 L at STP, what volume will it occupy at 35.00 oC and 1200. torr?
45. A gas occupies a volume of 250. mL at 25 °C and 630. torr pressure. Calculate the volume that the gas would occupy at 70. °C and 950. torr.
46. What pressure will 700. mL of a gas at STP exert when its volume is 250. mL at 45 °C?
47. A gas occupies 20. L at 130. °C and 2.0 atm. At what temperature will the gas occupy 34.5 L at 121,564 Pa?
48. A 3.00 L sample of air at –45.0 °C has a pressure of 750. torr. What will be the new pressure if the temperature is raised to 323 K and the volume is tripled?
49. At certain temperature and pressure, a balloon with 10.0 grams of O2 has a volume of 7.00 L. What is the volume after 5.00 grams of O2 is added to the balloon?
50. A metallic cylinder contains 18.0 grams of Argon gas. How many moles of Argon must be removed from the system in order to reduce the volume from 20.0 L to 7.5 L?
51. At certain conditions, 8.00 grams of N2 has a volume of 5.00 L. How many moles of N2 must be added to the system to generate a total volume of 12.3 L?
52. If 23.8 g of C2H6 gas occupies a volume of 15.0 mL at a particular temperature and pressure, what will 68.9 g of the gas occupy under the same condition?
53. Thirty grams of methane gas (CH4) occupies a 25 – L adjustable cylinder. A small hole causes the volume to decrease by half. How many moles of gas were left in the cylinder?
54. A 2.1 moles gas sample has a volume of 18.75 L at 392 K and 2.87 atm. What volume will it occupy after a mole of the same gas is added to the container under the same conditions?
55. Eighteen grams of Neon gas has a volume of twenty five liters. A small hole causes 10.0 L of Ne gas to escape in 40.0 seconds. How many moles of Ne gas were left?
56. At certain temperature and pressure, 8.75 grams of Cl2 has a volume of 5.10 L. What is the volume after 4.00 moles of chlorine gas is added?
57. If 0.250 mol of argon gas occupies a volume of 76.2 mL at a particular temperature and pressure, what volume would 0.430 mole of argon occupy under the same conditions?
58. How many moles of gas occupy a volume of 2.54 L if one mole of the same gas originally occupies a volume of 17.45 L?
59. If 23.1 grams of oxygen gas occupies a volume of 5.0 L at 25 °C and 750 torr, what volume will 2.50 g of oxygen gas occupy under the same conditions?
60. A 3.7-liter adjustable cylinder contains an unknown gas at 35 °C and 860 mmHg. What volume will it occupy if 0.45 moles of the same gas is added to the container under the same conditions?
61. Forty moles of H2 gas are pumped into a 20.0 L cylinder at 30.0 0C. What is the pressure inside the cylinder?
62. What volume will be occupied by 25.6 g O2 which is collected at 912 torr at 20.0 oC?
63. Calculate the molecular weight of a gas whose density is 1.23 g/L at 0.750 atm and 20.0 oC.
64. Calculate the density of CH4 gas at:
a. STP? b. 20.0 °C and 750. mmHg
65. Calculate the density of N2 at:
a. STP b. 30.0 °C and 700. mmHg
66. How many moles of gas are contained in a 34 L cylinder at a pressure of 600. torr and a temperature of 576 K?
67. How many moles of gas would be present in a 750.0 mL vessel at 30.5 ºC and a pressure of 199,365 Pa?
68. What volume in mL is occupied by a 56.27 g of NH3 gas at 40.0 ºC and 872 mmHg?
69. What is the molecular weight of a gas if 2.21 g of the gas occupies a volume of 1.72 L at 25.0 °C and 780.0 mmHg?
70. A pure gas has a density of 1.80 g/L at 20.0 °C and 1.88 atm. Calculate the molecular mass of the gas.
71. Calculate the density of the following gases at 2.50 atm and 298 K
a. CO2 b. N2O c. Cl2 d. H2O vapor
b. Which gas is most dense?
72. Calcium hydride, CaH2, reacts with water to form hydrogen gas. This reaction is sometimes used to inflate life rafts, weather balloon, and the like, where a simple, compact means of generating H2 is desired.
a. How many grams of H2 gas are produced if the reaction generated 10.0 L of H2 at 23.0 °C and 740. torr?
b. What is the density of hydrogen gas at these conditions?
73. A steel cylinder contains a mixture of nitrogen gas at 420.0 torr, oxygen gas at 110.0 torr, and helium gas at 230.0 torr. What is the total pressure of the gas mixture?
74. What is the total pressure in atmosphere of a gas mixture containing argon gas at 0.280 atm, helium gas at 280.0 mmHg and nitrogen gas at 390.0 torr?
75. A mixture of gases has the following partial pressures for the component gases at 20 °C in a volume of 2.0 L: O2 = 180 torr, N2 = 320 torr, H2 = 246 torr
a. Calculate the total pressure in torr.
b. Calculate the volume in liters at STP occupied by the gases remaining if H2 is selectively removed.
76. A 10.0-liter container at 25.0 °C contains a mixture of oxygen at 1.23 atm, helium at 5.40 atm, and xenon at 7.30 atm:
a. What is the total pressure exerted in the container?
b. What is the new pressure inside the container after the addition of 2.90 g sulfur dioxide (SO2)?
77. What are the partial pressures of H2 and He in the gaseous mixture of 1.00 gram H2 and 5.00 grams He when the mixture is confined to a volume of 5.00 L at 20.0 oC? What is the total pressure inside the container?
78. A container holds 3 gases: oxygen, carbon dioxide and methane. The partial pressures of the three gases are 790.0 torr, 198,345 Pascal, and 8754.78 mmHg, respectively. What is the total pressure, in atmosphere, inside the container?
79. Calculate the total pressure of a mixture that contains 2.50 g of He and 5.00 g of Argon in a 7.00 L container at 20.0 °C.
80. A sample of oxygen gas was collected by displacement of water at 25 °C and 1.02 atm total pressure. If the vapor pressure of water at 25.0 °C is 23.8 torr, what is the pressure of oxygen in the sample?
81. If 8.00 g of F2 and 8.00 g of Ne are placed in a 7.00 – L rigid container at 25.0 °C, what will be the partial pressure of each gas and the total pressure in the container?
82. Oxygen gas occupies 500. mL at 20.0 °C and 760. mmHg. What volume will it occupy if it is collected over water at 30.0 °C and 750. mmHg? The vapor pressure of water at 30.0 °C is 31.8 mmHg.
83. What is the partial pressure of each gas and the total pressure in the container if an 11.5 – L metallic cylinder at 30.0 °C contains 7.50 grams each of methane (CH4), nitrogen dioxide (NO2), and carbon monoxide (CO)?
84. The percent composition of air by volume is 78.08 % nitrogen, 20.95 % oxygen, 0.930 % argon, and 0.0360 % carbon dioxide. What are the partial pressures of these four gases in a sample of air at a barometric pressure of 748 mmHg?
85. Find the molar mass of a gas that diffuses 1.30 times as fast as oxygen gas, O2?
86. Calculate the molar mass of a gas that diffuses 1.25 times as fast as methane, CH4?
87. What is the molar mass of a gas that diffuses 0.50 times as fast as carbon dioxide, CO2?
88. What is the molecular mass of a gas which diffuses 0.33 times as fast as hydrogen gas?
89. Compare the rates of diffusion of the following gases:
a. HBr and SO2 c. CO2 and CO e. NH3 and HCl
b. O2 and H2 d. N2O3 and Ar
90. An unknown gas diffuses at the rate of 8.0 cm3/s in a piece of apparatus in which CH4 gas diffuses at 12.0 cm3/s. Find the approximate molecular weight of the unknown gas.
91. A sample of Kr escapes through a tiny hole in 87.3 seconds, and an unknown gas requires 42.9 seconds under identical conditions. What is the molar mass of the unknown gas if the molar mass of Kr is 84 g/mol?
92. Gas A is 9 times as dense as gas B. In a given diffusion apparatus at a certain temperature and pressure, gas B diffuses at a rate of 15 cm in 10 seconds. In the same apparatus and at the same temperature and pressure, how fast will gas A diffuse in 10 seconds?
93. A sample of argon gas escapes through a tiny hole in 78.2 seconds, and an unknown gas requires 36.9 seconds to escape under similar conditions of pressure and temperature. What is the molar mass of the unknown gas?
94. The rate of diffusion of a certain gas is twice that of another gas. If the molar mass of the other gas is 16 g/mol, what is the molecular mass of an unknown gas?
95. Ethane (C2H6) gas diffuses at the rate of 14.2 cm3/s in a piece of apparatus at STP. How fast will it take for ethyne (C2H2) gas to diffuse at the same conditions?
Answer Key Available on Thursday (December 8, 2011)
len,
ReplyDeletecan't upload the answer key,
kay mura na disarrange nko ang order
sa problems..
-sir carlo
uy naka shades! Done na. I hope the order is correct. x(^__^)X <---crossing my fingers!
ReplyDelete