Problem 10: Calculate the root mean square speed of hydrogen molecule at 800K.
Solution:
Step: 1 Overview
From the equation of
Kinetic Energy from
Kinetic Molecular Theory, We know that:
K.E=(3/2)kT
(1/2)mvrms2=(3/2)kT
mvrms2=3kT
vrms2=(3kT)/m
Where k is constant has the value of 1.38x10
-23Jmol
-1K
-1
Step: 2 Calculation
Given:
T=800K
k=1.38x10-23Jmol-1K-1
molecular mass of hydrogen molecule = 2 a.m.u = 2x1.67x10-27Kg = 3.34x10-27Kg
Solution:
According to above equation:
vrms2=(3kT)/m
vrms2=(3x1.38x10-23x800)/(3.34x10-27)
vrms2=(3.312x10-20)/(3.34x10-27)
vrms2=9.916x106
Taking square root both sides:
vrms=3148.96m/s2 (Ans)
