How many water molecules (h2o) can be produced from 6 molecules of hydrogen gas (purple) reacting with 6 molecules of oxygen gas (turquoise)? which reactant is the limiting reactant?

oxygen and hydrogen molecules
a. 6 water molecules, hydrogen is limiting
b. 3 water molecules, oxygen is limiting
c. 3 water molecules, hydrogen is limiting
d. 12 water molecules, oxygen is limiting

Hydrogen gas reacts with oxygen gas to form water according to the equation


From the coefficients in the reaction equation, we can see that it takes two molecules of hydrogen to react with one molecule of oxygen. Since we begin with equal amounts of both gasses, we can conclude that hydrogen is the limiting reactant because we use it up first. Thus, we use hydrogen for our stoichiometry that follows.


Thus, the answer is B, 6 water molecules are produced with hydrogen being the limiting reactant