Question

Standard enthalpy of vapourisation `Delta_("vap")H^(@)` for water at `100^(@)C` si 40.66 kJ `mol^(-1)`. The internal energy of vaporization of water at `100^(@)C` (in kJ `mol^(-1)`) is
(Assume water vapour to behave like an ideal gas)
A. `+37.56`
B. `-43.76`
C. `+43.76`
D. `+40.66`

Answer 1

Correct Answer - A
`DeltaH=DeltaE+Deltan(g)RT`
`40.66xx1000=DeltaE+(1)xx8.314xx373`
`DeltaE=37.56 kJ mol^(-1)`