A cylinder of fixed capacity 44.8 litres contains helium gas at standard pressure at temperature . What is the amount of heat need to rest that temperature of the gas by `15.00^@C ? [ R = 8.31 " J mol"^(-1)K^(-1)]`

Explanation

Volume of 1 mole of He at at S.T.P = 22.4 letres
Total volume of He at S.T.P = 44.8 litres
`:.` No of mole of He `n= (44.8)/(22.4)=2`
Molar specific heat of He (monoatomic gas) at constant volume ,
`C_V=3/2R=3/2xx8.31J mol^(-1) K^(-1)`
`:. DeltaT = 15^@C = 15K`
Here required `Q = nC_VDeltaT`
`=2xx3/2xx8.31xx15`
`=373.95J`