A standard cylinder of oxygen used in a hospital has gauge pressure = 2000 psi (13,800 kPa) and volume = 14L (0.014m³) at T = 295 K . How long will the cylinder last if the flow rate, measured at atmospheric pressure, is constant at 2.0 L/min?

Photons of light scatter off molecules, and the distance you can see through a gas is proportional to the mean free path of photons through the gas. Photons are not gas molecules, so the mean free path of a photon is not given by Equation 20.3, but its dependence on the number density of the gas and on the molecular radius is the same. Suppose you are in a smoggy city and can barely see buildings 500 m away. How far would you be able to see if the temperature suddenly rose from 20°C to a blazing hot 1500°C with the pressure unchanged?

Interstellar space, far from any stars, is filled with a very low density of hydrogen atoms (H, not H₂). The number density is about 1 atom/cm³ and the temperature is about 3 K. Estimate the pressure in interstellar space. Give your answer in Pa and in atm.

Equation 20.3 is the mean free path of a particle through a gas of identical particles of equal radius. An electron can be thought of as a point particle with zero radius. Electrons travel 3.0 km through the Stanford Linear Accelerator. In order for scattering losses to be negligible, the pressure inside the accelerator tube must be reduced to the point where the mean free path is at least 50 km. What is the maximum possible pressure inside the accelerator tube, assuming T = 20℃? Give your answer in both P_a and atm.

What is the pressure inside a 41.0-L container holding 105.0 kg of argon gas at 21.6°C?

If a scuba diver fills his lungs to full capacity of 4.8 L when 9.0 m below the surface of sea water, to what volume would his lungs expand if he quickly rose to the surface? Is this advisable?

A scuba tank when fully charged has an absolute pressure of 185 atm at 18°C. The volume of the tank is 11.3 L. What would the volume of the air be at 1.00 atm and at the same temperature?

How well does the ideal gas law describe the pressurized air in a scuba tank? To fill a typical scuba tank, an air compressor intakes about 2300 L of air at 1.0 atm and compresses this gas into the tank’s 12-L internal volume. If the filling process occurs at 20°C, show that a tank holds about 96 mol of air.

Assuming a typical nitrogen or oxygen molecule is about 0.3 nm in diameter, what percent of the room you are sitting in is taken up by the volume of the molecules themselves?