Long-term space missions require reclamation of the oxygen in the carbon dioxide exhaled by the crew. In one method of reclamation, 1.00 mol of carbon dioxide produces 1.00 mol of oxygen, with 1.00 mol of methane as a by-product. The methane is stored in a tank under pressure and is available to control the attitude of the spacecraft by controlled venting. A single astronaut exhales 1.13 kg of carbon dioxide each day. If the methane generated in the recycling of three astronauts' respiration during one week of flight is stored in an originally empty 120-L tank at-45.0°C, what is the final pressure in the tank? Need Help? MPa Read It

(a) Find the average time required for an oxygen molecule to diffuse through a 0.200-mm-thick tear layer on the cornea. (b) How much time is required to diffuse 0.500 cm3 of oxygen to the cornea if its surface area is 1.00 cm2?

Which one of the following statements is true? (a) The path on a PV diagram always goes from the smaller volume to the larger volume. (b) The path on a PV diagram always goes from the smaller pressure to the larger pressure. (c) The area under the path on a PV diagram is always equal to the work done on a gas. (d) The area under the path on a PV diagram is always equal in magnitude to the work done on a gas.

A 20.0-L tank of carbon dioxide gas (CO2) is at a pressure of 9.50 105 Pa and temperature of 19.0C (a) Calculate the temperature of the gas in Kelvin. (b) Use the ideal gas law to calculate the number of moles of gas in the tank. (c) Use the periodic table to compute the molecular weight of carbon dioxide, expressing it in grams per mole. (d) Obtain the number of grains of carbon dioxide in the tank. (e) A fire breaks out, raising the ambient temperature by 224.0 K while 82.0 g of gas leak out of the tank. Calculate the new temperature and the number of moles of gas remaining in the tank. (f) Using a technique analogous to that in Example 10.6b, find a symbolic expression for the final pressure, neglecting the change in volume of the tank. (g) Calculate the final pressure in the tank as a result of the fire and leakage.

Unreasonable Results (a) How many moles per cubic meter of an ideal gas are there at a pressure of 1.001014N/m2 and at 0C ? (b) What is unreasonable about this result? (c) Which premise or assumption is responsible?

You are working for an automobile tire company. Your supervisor is studying the effects of molecules striking the inner surface of the tire due to their thermal motion. He gives you the following data from a recent experiment. The air in a tire on a parked car was measured to have a gauge pressure of Pi = 1.65 atm on a day when the temperature was T = 6.5C. The car was then driven for a while and then measurements were taken again. The gauge pressure in the tire was then Pf = 1.95 atm and the interior volume of the tire had increased by 5.00%. (a) Your supervisor asks you to determine by what factor the rms speed of the air molecules had increased from the first measurement In the second. (b) He also hints at a proposal he is going to make to replace air in tires with argon. Will this change the factor by which the average speed of the molecules changes in the conditions described?

A cylinder contains a mixture of helium and argon gas in equilibrium at 150C. (a) What is the average kinetic energy for each type of gas molecule? (b) What is the rms speed of each type of molecule?

If the average kinetic energy of the molecules in an ideal gas initially at 20C doubles, what is the final temperature of the gas? (5.6) (a) 10C (b) 40C (c) 313C (d) 586C

(a) Using data from the previous problem, find the mass of nitrogen, oxygen, and argon in 1 mol of dry air. The molar mass of N2 is 28.0 g/mol, that of O2 is 32.0 g/mol, and that of argon is 39.9 g/mol. (b) Dry air is mixed with pentane 5 H12, molar mass 72.2 g/mol), an important constituent of gasoline, in an air-fuel ratio of 15:1 by mass (roughly typical for car engines). Find the partial pressure of pentane in this mixture at an overall pressure of 1.00 atm.

a.) An ideal gas is in a sealed container. By what factor does the gas temperature change if the volume is halved and the pressure is tripled? b.) An ideal gas is in a sealed container. By what factor does the gas temperature change if the volume is doubled and the pressure is tripled? c.) If you have two jars containing the same amount, n1=n2, and type of gas (for example, oxygen) and they are at the same temperature, T, what can you say about their pressure if the first jar has four times the volume of the second, V1 = 4V2?  Hint: use pV=nRT