At standard pressure, the total amount of heat required to completely vaporize a 100. gram sample of water at its boiling point is(1) 2.26 X 10 J (3) 2.26 X 103 J
(2) 2.26 X 102 J (4) 2.26 X 105 J
We know that the heat of vaporization of water is 2260 J/g. So 100 gram sample of water being completely vaporized needs 2260*100=2.26*10^5 J. So the answer is (4).
