if 3 moles of H2 react with two moles of o2 what is limiting reactant

H₂ is the limiting reactant.

Explanation:

H₂  reacts with O₂

The reaction would be

2H₂ + O₂ → 2H₂O

According to the balanced equation, 2 moles of H₂ reacts with 1 mole of O₂ to form 2 moles of H₂O.

The ratio of usage of H₂ and O₂ is 2 : 1 respectively

If 3 moles of H₂ and 2 moles of O₂ are present then:

3 moles of H₂ would require 1.5 moles of O₂                 ( 2 : 1 of H₂ and O₂ )

Out of 2 moles of O₂, 1.5 moles would be used and 0.5 mole would be in excess.

Therefore, H₂ is the limiting reactant as the number of moles of H₂ are not enough to use all the O₂.