Answer:6.48 kJ
Explanation:The molar heat of vaporization,
Δ
H
vap
, sometimes called the molar enthalpy of vaporization, tells you how much energy is needed in order to boil
1
mole of a given substance at its boiling point.
In water's case, a molar heat of vaporization of
40.66 kJ mol
−
1
means that you need to supply
40.66 kJ
of heat in order to boil
1
mole of water at its normal boiling point, i.e. at
100
∘
C
.