By Sunil Bhardwaj


Consider a cubical vessel containing the gas.

Suppose, Total number of molecules present in the gas = n,

lf m is the mass of each molecule of the gas and L is length of each side of the cube.

According to the kinetic theory of gases, the molecules of the gas are moving in different directions with different velocities.

Consider anyone molecule, moving with a velocity \(\nu \) cm/sec in any direction.

The velocity can be resolved into three mutually perpendicular components \( { \nu }_{ x }\), \({ \nu }_{ y }\) and \({ \nu }_{ z }\).

Now, consider the motion of the molecule due to component \({ \nu }_{ x }\) only.

Momentum of molecule just before it strikes the face \(AB = m{ \nu }_{ x }\)

Momentum of molecule just aftre the strikes the face \(AB = -m{ \nu }_{ x }\)

Change in Momentum = \(m{ \nu }_{ x }-\left( -m{ \nu }_{ x } \right) =2m{ \nu }_{ x }\)

Now total distance travelled by molecule to collide the same face again will be \(2l\)

Therefor Number of collision per unit time \(=\frac { { \nu }_{ x } }{ 2l }\)

MCQ on Gaseous State from Physical Chemistry
Prof. Gianfranco Coletti

Shared publicly - 2019-08-23 00:00:00

Don’t want your columns to simply stack in some grid tiers? Use a combination of different classes for each tier as needed. See the example below for a better idea of how it all works.

Prof. Maheshwar Sharon

Shared publicly - 2019-08-24 00:00:00

For grids that are the same from the smallest of devices to the largest, use the .col and .col-* classes. Specify a numbered class when you need a particularly sized column; otherwise, feel free to stick to


Shared publicly - 2023-02-28 11:09:52

this is


Shared publicly - 2023-02-28 10:48:10