Q.

A total of 48 J heat is given to one mole of helium kept in a cylinder. The temperature of helium increases by 2°C. The work done by the gas is (Given: R=8.31 J k-1 mol-1)                 [2024]

1 48 J  
2 23.1 J  
3 24.9 J  
4 72.9 J  

Ans.

(2)   

        Given : Q=48 J

         1st law of thermodynamics, Q=U+W

          48=nCvT+W

           48=(1)(3R2)(2)+W

           W=48-3×R

           W=48-3×(8.3)       

             W=23.1 J