Distribution of Speeds of Gas Molecules

IMPORTANT

Distribution of Speeds of Gas Molecules: Overview

This topic covers concepts such as Molecular Speeds, Maxwell's Distribution of Velocities, Mean Free Path, Temperature Effects on Maxwell's Speed Distribution, Mean Speed of Molecules, and Most Probable Speed of Molecules.

Important Questions on Distribution of Speeds of Gas Molecules

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IMPORTANT

The ratio amongst most probable velocity, mean velocity and root mean square velocity is given by

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In Maxwell-Boltzmann distribution, the fraction of gas molecules having energy between E and E+dE is proportional to

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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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Assertion: Consider a system of gas having N molecules; Instantaneous K.E. of few molecules can be greater than average K.E. of the molecules of the given gas.

Reason: Number of molecules having most probable speed is greater than number of molecules having average speed.

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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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Which of the following statement is wrong about Maxwell's distribution curve?

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What happens when the gas becomes hotter?

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How can we find the most probable speed of molecules using maxwell's distribution curve for velocities of molecules of a gas?

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Area under maxwell distribution represents the number of number of molecules per unit volume.

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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

HARD
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Explain Maxwell distribution of molecular speeds with necessary graph. 

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Define the following 

Mean free path

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Define the following

Free path

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The expression n(r)=n0e-αx4 represents the number density of molecules of a gas as a function of distance r from the origin. If it is known that the total number of molecules is proportional to n0α-P, then find the value of P.

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Assertion: The root mean square velocity of molecules of a gas having Maxwellian distribution of velocities is higher than their most probable velocity, at any temperature.

Reason: A very small number of molecules of a gas which possess very large velocities, increase the root mean square velocity, without affecting the most probable velocity.

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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.

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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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Assertion: Maxwell speed distribution graph is symmetric about most probable speed.

Reason: rms speed of ideal gas, depends upon its type (monoatomic, diatomic and polyatomic)