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 1027 kg.)
1301 
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?
0234 
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
6468 
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
0142 
In an ultrahighvacuum system, the pressure is measured to be 1.00 X 1010 torr (where 1 torr = 133 Pa). Assuming the molecular diameter is 3.00 % 1010 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
1194 
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
0153 
Show that the mean free path for the molecules of an ideal gas is
0170 
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 1010 m.)
0213 
Argon gas at atmospheric pressure and 20.0°C is confined in a 1.00m3 vessel. The effective hardsphere diameter of the argon atom is 3.10 X 1010 m. (a) Determine the mean free path . (b) Find the pressure when = 1.00 m. (c) Find the pressure when = 3.10 X 1010 m
0162 
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 rootmeansq
0160