July 21, 2009

This set of problems is still about the different gas laws: Boyle's Law, Charles' Law, Gay-Lussac's Law, Combined Gas , Ideal Gas Law. This time I included problems about the van der Waals equation of state. This is the van der Waals equation of state: The equation takes into account what the Ideal Gas Law does not: the intermolecular attraction of gas molecules (this is the correction factor for pressure) and the collective volume occupied by the individual gas molecules (this is the correction factor for volume).

Boyle's Law Problems

1.Calculate the pressure required to reduce the volume of 8.0 L of gas at a pressure of 1.306 atm to 14.0 L with the temperature remaining constant.
Answer: 0.746 atm
2.Under constant temperature, 3.0 L of a sample gas was allowed to expand to a final volume of 18.0 L. If the initial pressure of the gas was 0.815 atm, what was the final pressure of the gas after its expansion?
Answer: 0.136 atm
3.A sample of a gas which occupies 4.1 L has a pressure of 3 atm. Determine the resulting volume of the gas if the pressure is changed to 11 atm and the temperature is maintained constant.
Answer: 1.12 L
4.At a pressure of 9.192 atm, a sample of gas has a volume of 0.304 L. If the pressure is reduced to 3.446 atm, what will be the resulting volume of the gas? Temperature is maintained constant.
Answer: 0.811 L
5.At a pressure of 8.75 atm, a sample of gas has a volume of 0.685 L. If the pressure is reduced to 5.5 atm, what will be the resulting volume of the gas? Temperature is maintained constant.
Answer: 1.09 L
6.Calculate the pressure required to reduce the volume of 4000 mL of gas at a pressure of 1139 torr to 3000 mL with the temperature remaining constant.
Answer: 1519 torr
7.Under constant temperature, 9000 mL of a sample gas was allowed to expand to a final volume of 24000 mL. If the initial pressure of the gas was 5104 torr, what was the final pressure of the gas after its expansion?
Answer: 1914 torr
8.A sample of a gas which occupies 1.74 L has a pressure of 6 atm. Determine the resulting volume of the gas if the pressure is changed to 7 atm and the temperature is maintained constant.
Answer: 1.49 L
9.Calculate the pressure required to reduce the volume of 8000 mL of gas at a pressure of 454 torr to 6000 mL with the temperature remaining constant.
Answer: 605 torr
10.Under constant temperature, 9.0 L of a sample gas was allowed to expand to a final volume of 25.0 L. If the initial pressure of the gas was 31.417 atm, what was the final pressure of the gas after its expansion?
Answer: 11.31 atm

Charles' Law Problems

1.Calculate the final volume of a 3.52 L gas at 79° C when the temperature is brought down to 26° C as the pressure remains unchanged.
Answer: 2.99 L
2.A sample of gas with a volume of 12.0 L at 425° C was allowed to expand to 17.0 L while maintaining a constant pressure. What was the new temperature of the gas?
Answer: 716° C
3.A sample of gas with a volume of 3.0 L at -255° C was allowed to expand to 23.0 L while maintaining a constant pressure. What was the new temperature of the gas?
Answer: -135° C
4.Maintaining a constant pressure, a sample of gas having a volume of 10.0 L at -130° C is heated to 85° C. What is the final volume of the gas?
Answer: 25.0 L
5.22 L of gas at -119° C was compressed to 13 L at constant pressure. Determine the resulting temperature of the gas.
Answer: -182° C
6.A sample of gas with a volume of 7.0 L at -224° C was allowed to expand to 19.0 L while maintaining a constant pressure. What was the new temperature of the gas?
Answer: -140° C
7.Calculate the final volume of a 50.98 L gas at 85° C when the temperature is brought down to 20° C as the pressure remains unchanged.
Answer: 41.72 L
8.20 L of gas at -150° C was compressed to 6 L at constant pressure. Determine the resulting temperature of the gas.
Answer: -236° C
9.Maintaining a constant pressure, a sample of gas having a volume of 7.0 L at -224° C is heated to -70° C. What is the final volume of the gas?
Answer: 29.0 L
10.Calculate the final volume of a 5.98 L gas at 75° C when the temperature is brought down to 15° C as the pressure remains unchanged.
Answer: 4.95 L

Gay-Lussac's Law Problems

1.A sample of a gas sealed in a vessel was determined to have a pressure of 1.091 atm at 25° C. What would be the pressure of the gas if the vessel was heated to increase the temperature by 72° C?
Answer: 1.355 atm
2.A gas cylinder containing a certain gas is found to have a pressure of 0.886 atm at 41° C. If the cylinder is immersed in a cooling solution so that the temperature is lowered by 10° C, calculate the resulting pressure inside the cylinder.
Answer: 0.858 atm
3.A sample of a gas has a pressure of 13 atm and a temperature of 117° C. Find the corresponding change in the temperature if the pressure is (a) reduced to 6 atm, (b) tripled. Assume the volume of the gas is constant.
Answer: (a) -93° C, (b) 897° C
4.A sample of a gas sealed in a vessel was determined to have a pressure of 2.223 atm at 25° C. What would be the pressure of the gas if the vessel was heated to increase the temperature by 59° C?
Answer: 2.663 atm
5.A gas cylinder containing a certain gas is found to have a pressure of 10.461 atm at 41° C. If the cylinder is immersed in a cooling solution so that the temperature is lowered by 25° C, calculate the resulting pressure inside the cylinder.
Answer: 9.628 atm
6.A sample of a gas has a pressure of 16 atm and a temperature of -238° C. Find the corresponding change in the temperature if the pressure is (a) reduced to 5 atm, (b) tripled. Assume the volume of the gas is constant.
Answer: (a) -262° C, (b) -168° C
7.A sample of a gas sealed in a vessel was determined to have a pressure of 0.911 atm at 8° C. What would be the pressure of the gas if the vessel was heated to increase the temperature by 77° C?
Answer: 1.161 atm
8.A gas cylinder containing a certain gas is found to have a pressure of 1.298 atm at 81° C. If the cylinder is immersed in a cooling solution so that the temperature is lowered by 29° C, calculate the resulting pressure inside the cylinder.
Answer: 1.192 atm
9.A sample of a gas has a pressure of 8 atm and a temperature of 841° C. Find the corresponding change in the temperature if the pressure is (a) reduced to 3 atm, (b) tripled. Assume the volume of the gas is constant.
Answer: (a) 145° C, (b) 3069° C
10.A gas cylinder containing a certain gas is found to have a pressure of 35.133 atm at 75° C. If the cylinder is immersed in a cooling solution so that the temperature is lowered by 6° C, calculate the resulting pressure inside the cylinder.
Answer: 34.527 atm

Combined Gas Law Problems

1.21.73 L of a sample of gas has a pressure of 3.66 atm and a temperature of 20° C. After compressing the volume down to 1.1 L and increasing the temperature to 43° C, calculate the change in the pressure of the gas.
Answer: 77.977 atm
2.148.39 L of a sample of gas has a pressure of 1.07 atm and a temperature of 20° C. After compressing the volume down to 11.21 L and increasing the temperature to 59° C, calculate the change in the pressure of the gas.
Answer: 16.049 atm
3.An expandable air balloon containing 67.9 L of a sample of a gas has a pressure of 2.507 atm at 76° C. What will be the resulting volume of the gas if the pressure is changed to 10 atm and the temperature is increased by 10° C?
Answer: 17.5 L
4.21.28 L of a sample of gas has a pressure of 3.64 atm and a temperature of 18° C. After compressing the volume down to 5.8 L and increasing the temperature to 69° C, calculate the change in the pressure of the gas.
Answer: 15.696 atm
5.What will be the final temperature of a 12.12 L gas at 29° C if its volume is changed to 24.005 L and its pressure changed from 3.775 atm to 1.855 atm?
Answer: 21° C
6.What will be the final temperature of a 64.592 L gas at 18° C if its volume is changed to 11.988 L and its pressure changed from 3.637 atm to 13.676 atm?
Answer: -70° C
7.16.06 L of a sample of gas has a pressure of 3.6 atm and a temperature of 15° C. After compressing the volume down to 3.19 L and increasing the temperature to 59° C, calculate the change in the pressure of the gas.
Answer: 20.893 atm
8.An expandable air balloon containing 159.1 L of a sample of a gas has a pressure of 1.07 atm at 54° C. What will be the resulting volume of the gas if the pressure is changed to 9 atm and the temperature is increased by 31° C?
Answer: 20.7 L
9.What will be the final temperature of a 27.361 L gas at 14° C if its volume is changed to 5.121 L and its pressure changed from 1.053 atm to 15.409 atm?
Answer: 513° C
10.An expandable air balloon containing 95.8 L of a sample of a gas has a pressure of 1.301 atm at 82° C. What will be the resulting volume of the gas if the pressure is changed to 6 atm and the temperature is increased by 15° C?
Answer: 21.7 L

Ideal Gas Law Problems

1.Given a weight of 9.89 g of each of the following gases: (a) F2, (b) Ar, (c) O2, calculate the volume of each gas at STP. (mol. wt.: F2=37.9968, Ar=39.948, O2=31.9988)
Answer: (a) 5.83 L, (b) 5.55 L, (c) 6.92 L
2.Given a volume of 13.79 L of the following gases at STP : (a) Ne, (b) O2, (c) N2, find the weight in grams of each gas. (mol. wt.: Ne=20.179, O2=31.9988, N2=28.0134)
Answer: (a) 12.42 g, (b) 19.7 g, (c) 17.25 g
3.Calculate the volume of 7.055 mol of a gas confined in a sealed vessel with a pressure of 3.381 atm and a temperature of 19° C.
Answer: 49.998 L
4.A 39.886 L tank containing a sample of gas has a pressure of 4.059 atm and a temperature of 24° C. Find the moles of gas contained inside the tank.
Answer: 6.643 mol
5.Given a weight of 9.36 g of each of the following gases: (a) He, (b) N2O, (c) N2, calculate the volume of each gas at STP. (mol. wt.: He=4.0026, N2O=44.0128, N2=28.0134)
Answer: (a) 52.38 L, (b) 4.76 L, (c) 7.48 L
6.Given a volume of 12.48 L of the following gases at STP : (a) CH4, (b) Ne, (c) NH3, find the weight in grams of each gas. (mol. wt.: CH4=16.0426, Ne=20.179, NH3=17.0304)
Answer: (a) 8.94 g, (b) 11.24 g, (c) 9.49 g
7.A 13.818 L tank containing a sample of gas has a pressure of 9.377 atm and a temperature of 13° C. Find the moles of gas contained inside the tank.
Answer: 5.521 mol
8.Calculate the volume of 0.693 mol of a gas confined in a sealed vessel with a pressure of 1.638 atm and a temperature of 15° C.
Answer: 9.998 L
9.A 36.344 L tank containing a sample of gas has a pressure of 1.181 atm and a temperature of 73° C. Find the moles of gas contained inside the tank.
Answer: 1.512 mol
10.Calculate the volume of 1.064 mol of a gas confined in a sealed vessel with a pressure of 13.184 atm and a temperature of 29° C.
Answer: 2 L

Van Der Waals Equation Problems

1.What is the pressure inside a 13.00 L capacity pressure tank containing 8.49 mol of NH3 at 21° C using the (a) Ideal Gas equation, (b) the Van Der Waals equation? (Given: a = 4.17 L2-atm/mol2, b = 0.0371 L/mol, R = 0.082057 L-atm/mol-K)
Answer: (a) 15.76 atm; (b) 14.37 atm
2.Determine the volume occupied by 2.2 mol NH3 at 5.596 atm and 68° C as predicted by the (a) Ideal Gas equation, (b) Van Der Waals equation. (Given: a = 4.17 L2-atm/mol2, b = 0.0371 L/mol, R = 0.082057 L-atm/mol-K)
Answer: (a) 11.00 L, (b) 10.76 L
3.Calculate the amount in moles of CO2 which has a volume of 9.00 L at 118.718 atm and 17° C using Van Der Waals equation. (Given: a = 3.59 L2-atm/mol2, b = 0.0427 L/mol, R = 0.082057 L-atm/mol-K)
Answer: 61.93 mol
4.How many moles of CO will occupy a volume of 5.00 L at 34.324 atm and 75° C? Use the Van Der Waals equation. (Given: a = 1.49 L2-atm/mol2, b = 0.0399 L/mol, R = 0.082057 L-atm/mol-K)
Answer: 6.08 mol
5.0.18 mol of N2 occupies a volume of 18.00 L at 28° C. Calculate the pressure of the gas using (a) Ideal Gas equation, (b) Van Der Waals equation. (Given: a = 1.39 L2-atm/mol2, b = 0.0391 L/mol, R = 0.082057 L-atm/mol-K)
Answer: (a) 0.25 atm; (b) 0.25 atm
6.What volume will be occupied by 0.58 mol of HBr at 1.263 atm and 72° C? Calculate the volume using (a) Ideal Gas equation, (b) Van Der Waals equation. (Given: a = 4.45 L2-atm/mol2, b = 0.0443 L/mol, R = 0.082057 L-atm/mol-K)
Answer: (a) 13.00 L, (b) 12.94 L
7.What is the pressure inside a 22.00 L capacity pressure tank containing 122.36 mol of O2 at 20° C using the (a) Ideal Gas equation, (b) the Van Der Waals equation? (Given: a = 1.36 L2-atm/mol2, b = 0.0318 L/mol, R = 0.082057 L-atm/mol-K)
Answer: (a) 133.72 atm; (b) 120.38 atm
8.17.18 mol of CO occupies a volume of 21.00 L at 42° C. Calculate the pressure of the gas using (a) Ideal Gas equation, (b) Van Der Waals equation. (Given: a = 1.49 L2-atm/mol2, b = 0.0399 L/mol, R = 0.082057 L-atm/mol-K)
Answer: (a) 21.15 atm; (b) 20.86 atm
9.Determine the volume occupied by 39.91 mol CO2 at 119.534 atm and 19° C as predicted by the (a) Ideal Gas equation, (b) Van Der Waals equation. (Given: a = 3.59 L2-atm/mol2, b = 0.0427 L/mol, R = 0.082057 L-atm/mol-K)
Answer: (a) 8.00 L, (b) 6.28 L
10.How many moles of O2 will occupy a volume of 21.00 L at 41.694 atm and 38° C? Use the Van Der Waals equation. (Given: a = 1.36 L2-atm/mol2, b = 0.0318 L/mol, R = 0.082057 L-atm/mol-K)
Answer: 35.36 mol
11.Calculate the amount in moles of Ne which has a volume of 16.00 L at 33.865 atm and 57° C using Van Der Waals equation. (Given: a = 0.211 L2-atm/mol2, b = 0.0171 L/mol, R = 0.082057 L-atm/mol-K)
Answer: 19.77 mol