The external pressure `2` atm is applied on frictionless movable piston, fitted in a vessel containing `100` g of X(g) at `450` K. now heat is sulplied keeping pressure constant till `40` g of Xis evaporated to to from X(g) at `500` K (boinling poing ). Calculate change in internal `(DeltaU)` energy in kJ for overall process. Assume vapour of X (l) behaves like an ideal gas.
Given : Molar hect capacity of X (l) =`60` J/mol K: `DeltaH_("vaporisation")`=30kJ/mol,`DeltaH_("vaporisation")`=30kJ/mol,R=8.3J/mol-K
At weight of X = `20 g//mol`.

Answer

6670