Work done in expansion of an ideal gas from `4` litre to `6` litre against a constant external pressure of `2.1 atm` was used to heat up `1` mole of water at `293 K`. If specific heat of water is `4.2 J g^(-1)K^(-1)`, what is the final temperature of water?

Explanation

`W-2.1[6-4]=-2.1xx2`
`= -4.2 atmxxlit`
`= -4.2xx101.325J`
This work is used to heat up the water
specific heat of `H_(2)O=4.2(J)/("gram".K)`
Heat required for increasing temperature by `1^(@)C` of `1 "mole"=4.2xx18=75.6 J`
`4.2xx101.325=75.6[T-293]`
`5.63=T-293`
`T=298.63K`