A swimmer coming out from a pool is covered with a film of water weighing about 18g. How much heat must be supplied to evaporate this water at 298 K? Calculate the internal energy of vaporisation at 100^@C. DeltaH_(vap)^@ for water at 373K = 40.66 kJ mol^(-1)

A swimmer coming out from a pool is covered with a film of water weigh

1.	A swimmer coming out from a pool is covered with a film of water weighing about 18g. How much heat must be supplied to evaporate this water at 298 K? Calculate the internal energy of vaporisation at 100^@C. DeltaH_(vap)^@ for water at 373K = 40.66 kJ mol^(-1)
Answer» Solution :We can represent the PROCESS of EVAPORATION as `H_(2)O_((l)) overset("vaporisation")(rarr)H_2O_((g)) , DELTA = 1 - 0 = 1` `Delta_(vap) E = Delta_(vap)H - pDeltaV =Delta_(vap) H - DeltanRT` (assumig steam BEHAVING as an ideal gas). `Delta_(vap) E = 40.66 kJ mol^(-1) - (1)` `(8.314 xx 10^(-3) KJ K^(-1) mol^(-1))(373 K) = 37.56 kJ mol^(-1)`.