Answer:
Reactant : A combustion of hydrocarbon.
Explanation:
It is known that when hydrocarbons are involved in combustion, they produce carbon dioxide and water.
CxHy + (x+y/4)O2 ===> xCO2 + y/2H2O
Divide the number of molecules you have by, 6.022 x 10^23. This will give you the moles of water, or the moles of anything, since there is always 6.022 x 10^23 molecules in 1 mole of substance.
1.23x10^24 atoms/6.022x10^23 atom/mole = 2.04 mole H20
