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

EASY
IMPORTANT

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

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IMPORTANT

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

EASY
IMPORTANT

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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IMPORTANT

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:

MEDIUM
IMPORTANT

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

HARD
IMPORTANT

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.

HARD
IMPORTANT

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

HARD
IMPORTANT

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

EASY
IMPORTANT

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

MEDIUM
IMPORTANT

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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IMPORTANT

Define the following 

Mean free path

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Define the following

Free path

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The temperature of an ideal gas is increased from 120 K to 480 K. If at 120 K, the RMS velocity of the gas molecules is vrms, then at 480 K it becomes:

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IMPORTANT

0.014 kg of nitrogen is enclosed in a vessel at a temperature of 27 °C. At which temperature the rms velocity of nitrogen gas is twice it’s the rms velocity at 27 °C ?

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IMPORTANT

A gas is filled in a container at pressure P0. If the mass of molecules is halved and their rms speed is doubled, then the resultant pressure would be

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IMPORTANT

In the following a statement of Assertion is followed by a statement of Reason.

Assertion: Mean free path of a gas molecule is inversely proportional to the density of gas.

Reason: Path of a gas molecule between two adjacent collision is straight line.