Estimate the number of collisions per second suffered by a molecule in a sample of hydrogen at STP. The mean free path (average distance covered by a molecule between successive collisions) = 1.38 × 10–5 cm.

Number of collision per second means frequency of collision.


In kinetic theory of ideal gas, the average energy is given by



Where R=gas constant=8.31Jmol-1K-1


T-temperature of gas


M=molar mass of gas


Molar mass of hydrogen =2 amu=2kg/mol




Given


Distance between successive collision 1.38 × 10–5 cm


1.3810-8m


Time between two collisions




Frequency of collision =


Number of collision per second means frequency of collision which is equal to 1.231011.


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