How many grams of H2O(l) would be made to react if 58.9 kJ of energy were provided?

Question

The following thermochemical equation is for the reaction of water(l) to form hydrogen(g) and oxygen(g).

1. 2H₂O(l)2H₂(g) + O₂(g)    H = 572 kJ

How many grams of H₂O(l) would be made to react if 58.9 kJ of energy were provided?

gram

Answer 1

572 kJ/2 moles H2O = 286 kJ/mole H2O

58.9 kJ x 1 mol H2O/286 kJ = 0.2059 moles H2O

grams H2O = 0.2059 mol H2O x 18 g/mol = 3.71 g H2O

Answer 2

Fro each and every 36.02 grams (2 moles x 18.01 g/mole) of liquid water to decompose, 572 kJ of energy must be provided.Now, 58.9 kJ of energy were available, therefore,

58.9 kJ x 36.02 g water/572 kJ = 3.71 g (liq). water