The answer is steel because you cannot pick water, oxygen, or gold out of a mixture.
Every time you see molecules, atoms, & particles think of avagadros #. (6.022 x 10^23)
Answer: 13.6 grams of H2O
Solution: (4.56x10^23) x (1 mol H2O/6.022x10^23) x (18 grams H2O/1 mol H2O) = 13.6 grams of H2O
Using dimensional analysis above makes these types of problems easy.
This is called a combustion reaction. A combustion reaction involves oxygen gas. Most combustion reaction are exothermic as they give off heat. When organic molecules (containing carbon and hydrogen) combust the reaction products are carbon dioxide and water as well as heat or light. Combustion reactions may be complete or incomplete, a complete combustion releases more energy than incomplete combustion.
Dipole-dipole interactions, and London dispersion interactions