From the equation, we can see that the molar ratio between hydrogen and oxygen is:
2 : 1
Next, we determine the moles of hydrogen and oxygen that are actually present using:
moles = mass / Mr
Hydrogen:
moles = 4 / 2 = 2
Oxygen:
10/32 = 0.3125
Therefore, it is evident that the moles of oxygen present, 0.3125, are less than those that are required for 2 moles of hydrogen, which is 1. This makes oxygen the limiting reactant, which is the one that limits the completion of a reaction.
