Showing 41 to 50 of 465 Questions
  • At what temperature would the average speed of helium atoms equal? (a) The escape speed from Earth, 1.12 X 104 m/s and (b) The escape speed from the Moon, 2.37 X 103 m/s? (See Chapter 13 for a discussion of escape speed, and note that the mass of a helium atom is 6.64 X 10-27 kg.)

  • A gas is at 0°C. If we wish to double the rms speed of its molecules, to what temperature must the gas be brought?

  • Assume that the Earth’s atmosphere has a uniform temperature of 20°C and uniform composition, with an effective molar mass of 28.9 g/mol. (a) Show that the number density of molecules depends on height according to nv(y) = nOe –mgy/kBT Where n0 is the number density at sea level, where y = 0. This result is called the law of atmosp

  • If you can’t walk to outer space, can you at least walk halfway? Using the law of atmospheres from Problem 43, we find that the average height of a molecule in the Earth’s atmosphere is given by

  • In an ultra-high-vacuum system, the pressure is measured to be 1.00 X 10-10 torr (where 1 torr = 133 Pa). Assuming the molecular diameter is 3.00 % 10-10 m, the average molecular speed is 500 m/s, and the temperature is 300 K, find (a) The number of molecules in a volume of 1.00 m3, (b) The mean free path of the molecules, and (c) Th

  • In deep space the number density of particles can be one particle per cubic meter. Using the average temperature of 3.00 K and assuming the particle is H2 with a diameter of 0.200 nm, (a) Determine the mean free path of the particle and the average time between collisions. (b) What If? Repeat part (a) assuming a density of one particl

  • Show that the mean free path for the molecules of an ideal gas is

  • In a tank full of oxygen, how many molecular diameters d (on average) does an oxygen molecule travel (at 1.00 atm and 20.0°C) before colliding with another O2 molecule? (The diameter of the O2 molecule is approximately 3.60 X 10-10 m.)

  • Argon gas at atmospheric pressure and 20.0°C is confined in a 1.00-m3 vessel. The effective hard-sphere diameter of the argon atom is 3.10 X 10-10 m. (a) Determine the mean free path . (b) Find the pressure when = 1.00 m. (c) Find the pressure when = 3.10 X 10-10 m

  • The dimensions of a room are 4.20 m X 3.00 m X 2.50 m. (a) Find the number of molecules of air in the room at atmospheric pressure and 20.0°C. (b) Find the mass of this air, assuming that the air consists of diatomic molecules with molar mass 28.9 g/mol. (c) Find the average kinetic energy of one molecule. (d) Find the root-mean-sq