59.87 kJ
In the question , we are given;
We are required to calculate the amount of heat energy absorbed to convert water at 100°C to steam at 100°C.
Moles = Mass ÷ Molar mass
Molar mass of water = 18.02 g/mol
Moles of water = 100 g ÷ 18.02 g/mol
            = 5.549 moles
But;
Q = n × ΔHv , where n is the number of moles and ΔHv molar heat of Vaporization.
Therefore;
Q = 5.549 moles × 10.79 kJ/mol
  = 59.874 kJ
  = 59.87 kJ
Thus, the amount of heat absorbed is 59.87 kJ