Equal masses (in grams) of hydrogen gas and oxygen gas are reacted to form water. Which substance is limiting?
a. Oxygen gas is limiting
b. Hydrogen gas is limiting.
c. Water is limiting.
d. Nothing is limiting.
e. More information is needed to answer this question

a. Oxygen gas is limiting

Explanation:

2H₂ + O₂  →  2H₂O

the above balanced equation shows that 2 moles of H₂ is required for 1 mole of O₂

Given equal masses of H₂ and O₂

assuming 'x' gm for each, no. of moles of each gas  =

no. of moles of H₂ = x/2 = 0.5x moles

no.of moles of O₂ = x/32 = 0.031x moles

This shows that no. of moles of O₂ is very less so O₂ will become the limiting reagent.