Mean Free Path and RMS Speed

IMPORTANT

Mean Free Path and RMS Speed: Overview

This topic covers concepts, such as, Mean Free Path & Time for Successive Collisions between Walls etc.

Important Questions on Mean Free Path and RMS Speed

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The mean free path of molecules of a certain gas at STP is 1500d, where d is the diameter of the gas molecules. While maintaining the standard pressure, the mean free path of the molecules at 373 K is approximately:

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In a gas at STP, if n is the number density of the molecules and r is the radius of the molecule, then the mean free path of the molecule is inversely proportional to

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The collision frequency of nitrogen molecule in a cylinder containing at 2.0 atm pressure and temperature 17°C is approximately: (Take radius of a nitrogen molecule is 1.0 )

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Time for successive collisions between walls :-

(ii) Time for two successive collision between the walls is.

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Time for successive collisions between walls ;-

(i) When there is collision between two walls then charge in momentum per second is along X- axis.

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Derive the formula for time for successive collision between the walls of the container with the molecule.

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For a gas with n number of molecules per unit volume, Suppose the molecules of a gas are spheres of diameter d  the average speed of each molecule is v. The time between two successive collisions is on the average Γ=1nπvd2

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The mean free path and RMS velocity of a nitrogen molecule at a temperature 17 °C are 1.2×10-7 m and 5×102 m s-1, respectively. The mean time between two successive collisions will be x×10-11 s, what is the value of x.

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The mean free path of molecules of a gas (radius ‘r’) is inversely proportional to r2.

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The mean free path (λ) of a gas sample is given by:

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If the temperature and pressure of a gas is doubled the mean free path of the gas molecules

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Calculate the time taken between two successive collisions for a helium molecule having a diameter 7×10-10 m and an average velocity of 103 m/s, consider 1030 molecules present per unit volume.

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Derive the formula of the time interval between two successive collisions of molecules.

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For a molecule of an ideal gas, the number density is 22×108 cm-3 and the mean free path is 10-2π cm. The diameter of the gas molecule is

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Consider an ideal gas confined in an isolated closed chamber. As the gas undergoes an adiabatic expansion, the average time of collision between molecules increases as Vq, where V is the volume of the gas. The value of q is :- γ=CpCv

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The velocity of five particles in m s-1 are 3, 9, 4, 15, 2. Calculate r.m.s. speed in m s-1.

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The root mean square velocity of a perfect gas is

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The root mean square velocity of a gas molecule at 27  is 1365 m s-1. The gas is

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At what temperature is the root mean square speed of oxygen atom equal to the root mean square speed of helium gas atom at -10 ? Atomic mass of oxygen =32 and that of helium =4.

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Define the following 

Mean free path