The standard molar heat of vaporization for water is 40.79 kj/mol. how much energy would be required to vaporize 5.00 mol h2o

             203.95 kJ

Solution:
               Heat of vaporization is the amount of energy which is required to convert a substance from liquid state to gas state. In given problem it is given that for 1 mole of water (18 g) 40.79 kJ heat is required to convert it into steam, and for 5 moles of H₂O (90 g) the amount of heat required is calculated as,

As

                         1 mole of water requires 40.79 kJ heat,

So,

                                           5 mole of water will require,

                                      =  (5 mol × 40.79 kJ) ÷ 1 mol

                                      =  203.95 kJ

Ido not understand.