A balloon has 5.0 mole of helium at `7^(@)C`. Calculate the total internal energy of the system.

Options

A. `1.64xx10^(4)J`
B. `210xx10^(4)J`
C. `1.74xx10^(4)J`
D. `1.53xx10^(4)J`

Answer

C

Explanation

Here ,`mu=5 and T=(273+7)K=280K`
Number of atoms = `muN_(A)=5xx6.02xx10^(23)=30xx10^(23)`
Average Kintic energy per molecule = `(3)/(2)k_(B)T`
`therefore` Total internet energy `=(3)/(2)k_(B)TxxN,K_(B)=1.38xx10^(-23)` (mks units)
`=(3)/(2)xx30xx10^(23)xx1.38xx10^(-23)xx280=1.74xx10^(4)J`