12.9: End of Chapter Problems
Gases and Pressure
1. How many atmospheres are in 1,547 mm of Hg?
2. How many millimeters of mercury are in 9.65 atm?
3. Covert 9.2 psi to:
a. atm.
b. torr.
4. Explain how a barometer works?
5. What is systolic pressure and diastolic pressure?
6. What is STP?
7. If you go camping in the mountains, why does it take longer to cook rice than it does at sea level? Explain with the help of the vapor pressure concept.
8. Explain the working of the autoclave with the help of the vapor pressure concept.
Gas Law Applications
Identify the gas laws involved in the following problems:
1. What is the relationship between temperature and pressure that must be kept in mind when oxygen cylinders are in use at the hospital ?
2. Aerosol cans should be stored in a cool place. Why? Explain with the help of a gas law.
3. Early winter, your tires on your car look deflated. Why? Explain with the help of a gas law.
4. Rapid ascent in an elevator may cause the volume of intestinal gas to increase and cause intestinal cramps. Why? Explain with the help of a gas law.
5. In respiration (exhaling), explain how changes in pressure in chest cavity changes the volume of the lungs. What gas law applies?
6. In respiration (inhaling), explain how changes in pressure in chest cavity changes the volume of the lungs. What gas law applies?
7. Suppose you were diving rather deep in the ocean and had to surface quickly while leaving your tank at the bottom. What precaution would you take so as not to put pressure on your lungs ? Gas law?
8. During severe bleeding, ADH (a hormone released by the hypothalamus) causes vasoconstriction (shrinking of the blood vessels) to take place. What effect does a decrease in blood vessel volume have on blood pressure?
9. What happens to the solubility of carbon dioxide gas in water when:
a. the pressure of CO 2 over the solution is increased.
b. the temperature is increased.
10. Why is breathing 100% O 2 in a pressurized hyperbaric chamber more effective at treating gangrene than breathing 100% O 2 at atmospheric pressure?
11. What is Bends? Explain with the help of a solubility law.
12. Two unopened bottles of carbonated water are at the same temperature. If one is opened at the top of a mountain and the other at sea level, which will produce more bubbles? Explain
13. Some people with respiratory problems is very uncomfortable in low pressure air that is very moist. Why
Gas Laws Calculations
Identify the gas laws involved in the following problems:
1. The pressure of an oxygen tank containing 15.0 L oxygen is 965 torr at 55.0 o C. What will be the pressure when the tank is cooled to 16.0 o C.
2. A sample of CO 2 occupies 3.23 L volume at 25.0 o C. Calculate the volume of the gas at 50.0 o C if pressure and amount of gas do not change?
3. The pressure of a 1.32 L sample of SO 2 gas at 0.532 atm is increased to 1.231 atm. Calculate the new volume of the gas if the temperature and the quantity of the gas remain the same?
4. An oxygen tank holds 20.0 L of oxygen at a pressure of 10.0 atm. What is the final pressure when the gas is released and occupies a volume of 200. L?
5. A weather balloon contains 212 L of helium at 25.0∘C and 750. mmHg. What is the volume of the balloon when it ascends to an altitude where the temperature is −40.0∘C and 540. mmHg, assuming the quantity of gas remains the same?
6. A sample of a gas at a temperature of 37.0 o C has a pressure of 725 torr and occupies a volume of 3.44 L.
a. Calculate the new pressure is the temperature is held constant and the volume is increased to 6.17 L.
b. Calculate the new pressure if the volume is held constant and the temperature is decreased to 10.0 o C.
c. Calculate the new volume if the pressure is held constant and the temperature is increased to 150.0 o C.
d. Calculate the new pressure if the temperature is decreased to 25.0 o C and the volume is increased to 15.9 L.
Respiration and Gases
1. Explain with the concept of partial pressures how oxygen gas (O 2 ) moves from the lungs to the tissues.
2. Explain with the concept of partial pressures how carbon dioxide gas (CO 2 ) moves from the tissues to the lungs.
3. Some runners train at high altitudes. Why?
4. Why does O 2 have greater solubility in blood than in water?