JEE Main 2014PhysicsKinetic Theory of GasesMediumMCQ

JEE Main 2014 — Kinetic Theory of Gases Question with Solution

JEE Main 2014 (09 Apr Online)

Question

Modern vacuum pumps can evacuate a vessel down to a pressure of 4.0 × 1 0 - 1 5  atm. at room temperature (300 K). Taking R = 8.3 JK-1  mole-1, 1 atm = 105 Pa and N Avogadro = 6 × 1 0 2 3 mole - 1 , the mean distance between molecules of gas in an evacuated vessel will be of the order of :

Choose an option

Show full solutionCorrect option: B
Correct answer
B0.2 mm

Step-by-step explanation

Let the inter molecular distance be D
Then in a volume of 4 3 π D 3 there is only one molecule.

4 3 π D 3 P=( 1 N A )RT

D= ( 3RT 4π N A P ) 1 3

Substituting P=4× 10 −10 Pa,  R=8.3,   N A =6× 10 23 ,  T=300K

D=0.2 mm

 

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About this question

This is a previous-year question from JEE Main 2014, covering the Kinetic Theory of Gases chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.