The average distance traveled by a molecule between successive collisions is called mean free path. For a given amount of a gas, how does the mean free path of a gas depend on (a) density, (b) temperature at constant volume, (c) pressure at constant temperature, (d) volume at constant temperature, and (e) size of the atoms?

Short Answer

Expert verified
The mean free path depends inverse proportionally on density, pressure at constant temperature and size of the atoms, but is directly proportional on volume at constant temperature. There's no significant effect of temperature at constant volume on the mean free path.

Step by step solution

01

(a) Dependency on Density

The mean free path of a gas is inversely proportional to its density. When the density of a gas increases, the number of molecules per unit volume also increases, resulting in more frequent collisions and hence, a shorter mean free path.
02

(b) Dependency on Temperature at Constant Volume

The mean free path is not directly affected by the temperature of a gas at constant volume. This is due to the fact that a change in temperature at constant volume does not significantly alter the density of the gas, thus it does not affect the average distance that molecules travel between collisions.
03

(c) Dependency on Pressure at Constant Temperature

The mean free path of a gas is inversely proportional to its pressure at constant temperature. When the pressure of a gas increases at constant temperature, the density of the gas also increases, leading to more frequent collisions and hence, a shorter mean free path.
04

(d) Dependency on Volume at Constant Temperature

The mean free path of a gas is directly proportional to its volume at constant temperature. When the volume of a gas increases at constant temperature, the density of the gas decreases, leading to less frequent collisions and hence, a longer mean free path.
05

(e) Dependency on Size of the Atoms

The mean free path of a gas is inversely proportional to the size of its atoms. The larger the size of the atoms, the greater the chances of collisions, and thus, the shorter the mean free path.

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