Question

`5` moles of a liqiud `L` are converted into its vapour at its boiling point `( 273^(@)C)` and at a pressure of `1 "atm"`. If the value of latent heat of vapourisation of liquid `L` is `273 L atm//"mole"`, then which of the following statements is`//`are correct. Assume volume of liquid to be negligible and valpour of the liquid to behave ideally.
A. Work done by the system in the above process is `224 L` atm.
B. The enthalpy change `(Delta H)` for the above process is `1365 L` atm (with respect to magnitude only)
C. The internal energy of the system increases in the above process.
D. The value of `Delta U` for the above process is `1589 L` atm.

Answer 1

Correct Answer - A::B::C
`1xxV_(t)=5xxRxx546=224 L`
`W= -P_(ext)(Delta V)= -1 "atm"(224 L)= -224 L "atm"`
`:.` work done by system `=224 L "atm"`
Enthalpy change `(DeltaE)=q=273.xx5 =1365 K atm`
`Delta U= q+W=1365-224=1141 L "atm"`