Question

The root mean square speed of 8 g of He is 300 `ms_(-1)`. Total kinetic energy of He gas is :
A. 120 J
B. 240 J
C. 360 J
D. None of these

Answer 1

Correct Answer - c
(c) `300=sqrt((3RT)/(4xx10^(-3)))," "RT=120`
Total K.E. of He gas`=(3)/(2)nRT`
`=(3)/(2)xx(8)/(4)xx120J`
`=360J`