A tank of volume `0.2 m^(3)` contains helilum gas at a temp. of `300` K and pressure `10^(5) N//m^(2)` . Find the amount of heat required to raise the temp. to `500` K. The molar heat capacity of helium at constant volume is `3.0 cal//mol e-K` . Neglect any expansion in the volume of the tank. Take `R=8.31 j//mol e -K`.

Answer

`[4813.2 cal.]`

Explanation

Amount of gas in moles
`n=(pV)/(RT)=(10^(5)xx0.2)/(8.31xx300)=8.022`
`:.` The amt. of heat required, `Delta Q=nC_(v) Delta T`
`=8.022xx3.0xx(500-300)=4813.2 cal`