3RD QUARTER S.Y. 2012-2013: GAS LAWS

GAS LAWS

1. The volume of a person's lungs is 600.0 mL at a pressure of 760 mmHg. By how much will the pressure drop when the lungs expand to 610.0 mL?

ANSWER: 12.46 mmHg ~ 12 mmHg (Pressure dropped from 760 mmHg to 747.54 mmHg)

2.  What is the volume of a sample of oxygen at 3.0 degrees Celsius and 744 torr if it occupies 13.3 L at 55 degrees Celsius and 744 torr?

ANSWER: 11.19L ~ 11L

3.  An aerosol container has a pressure of 3.0 atm at 30 degrees Celsius. What is the new pressure in the aerosol container if it is thrown into a fire with a temperature of 550 degrees Celsius? The aerosol can may explode if the pressure exceeds 7.0 atm. Would you expect the can to explode?

ANSWER: 8.15 atm ~ 8 atm

4.  A high altitude balloon is filled with 1.2 x 10^4 L (12,000 L) of helium at a temperature of 27 degrees Celsius and a pressure of 760 torr. What is the volume of this balloon at a height of 10 km, where the temperature is -25 degrees Celsius and the pressure of 63 torr?

ANSWER: 119,682.38 L ~ 120,000 L

5.  At STP, a gas has a volume of 8.00 L. What volume will the gas occupy at 50 degrees Celsius and 600 torr? 

ANSWER: 11.995 L ~ 10 L

6.  A 3.00 L flask contains 2.33 g argon gas at 312 mmHg. What is the temperature of the gas? 

ANSWER: 257.149 K ~ 257 K

7.  The composition (in mole percent) of the atmosphere is 78.1% N2, 21.0% O2 and 0.9% Ar. What is the partial pressure of each gas when the barometric pressure is 754.1 mmHg?

ANSWER: Oxygen = 158.4 mmHg; Nitrogen = 588.95 mmHg; Argon = 6.79 mmHg

8.  A volatile compound with a mass of 0.8822 grams is placed in an evacuated 0.250 L flask. The flask is heated to evaporate the compound. At 99 degrees Celsius, the pressure in the flask is 1.25 atm. What is the molar mass of the compound? 

ANSWER: 86.25 g/mol ~ 86 g/mol

9.  A certain gas diffuses at a rate of 85 cm^3/s in a diffusion apparatus in which a second gas, He, whose molecular weight is 4.0 g/mol, diffuses at the rate of 224.9 cm^3/s. Calculate the molecular weight of the gas.

ANSWER: 28 g/mol

10.  At certain temperature and pressure, 88.75 grams of chlorine gas has a volume of 5.10 L. What is the volume after 4.00 moles of chlorine gas is added?

ANSWER: 21.4 L 

HAPPY LONG TEST EVERYONE!