Question

According to pressure equation, PV=1/3 M Vrms².

=>nRT=1/3 M Vrms²

=> T directly proportional to M Vrms²

According to mean Kinetic energy,

KE(avg)=1/2 M Vrms²

=> KE(avg) directly proportional to M Vrms²

This means.. M Vrms² directly proportional to KE(avg) T

=> M Vrms² /T = KE(avg) × proportionality constant

So this means the avg Kinetic energy is inversely proportional to Absolute Temperature. But actually KE(avg) is directly proportional to T. Please clear my doubt

Answer 1

You did calculation mistake in this expression

M Vrms² /T = KE(avg) × proportionality constant

Here is the explanation

PV=1/3 M Vrms²

nRT = 1/3 M Vrms²

M Vrms² / T = Proportionality constant

T is directly proportional to M Vrms²

KE(avg)=1/2 M Vrms²


KE (avg) is directly proportional to M Vrms²

So KE (avg) is directly proportional to T

This statement is wrong M Vrms² /T = KE(avg) × proportionality constant

Correct statement will be

M Vrms² /T = KE(avg) /T = Proportionality constant