A common misconception is that the following chemical reaction occurs when water is boiled: 2H2O(l) 2H2(g)

Question:

A common misconception is that the following chemical reaction occurs when water is boiled:
2H2O(l) → 2H2(g) + O2(g)
instead of
H2O(l) → H2O(g)
a. What evidence do you have that the second reaction is correct?
b. How would the enthalpy of the wrong reaction compare with that of the correct reaction?
c. How could you calculate the enthalpy change for the wrong reaction?