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Calculate the enthalpy of vaporisation p...

Calculate the enthalpy of vaporisation per mole for ethanol. Given `DeltaS = 109.8 J K^(-1) mol^(-1)` and boiling point of ethanol is `78.5^(@)`.

Text Solution

Verified by Experts

The entropy change for vaporisation,
`Delta_(vap)S^(Theta) = (Delta_(vap)H)/(T_(b))`
or `Delta_(vap)H^(Theta) = Delta_(vap)S^(Theta)T_(b)`
`DeltaS^(Theta) = 109.8 J K^(-1)mol^(-1), T_(b) = 273 +78.5 = 351.5K`
`:. DeltaH^(Theta) = (109.8 xx 351.5) = 38.595 kJ mol^(-1)`
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