1. Balanced Chemical Equation

First, we need the balanced chemical equation for the reaction between hydrogen (H₂) and oxygen (O₂) to form water (H₂O):

2 H₂ + O₂ → 2 H₂O

2. Mole Ratio

The balanced equation tells us that 2 moles of H₂ react with 1 mole of O₂.

3. Calculation

We have 5.0 moles of O₂. Using the mole ratio from the balanced equation, we can set up a proportion:

(2 moles H₂) / (1 mole O₂) = (x moles H₂) / (5.0 moles O₂)

Solving for x (moles of H₂):

x = (2 moles H₂) * (5.0 moles O₂) / (1 mole O₂) = 10 moles H₂

Answer: You need 10 moles of H₂ to react with 5.0 moles of O₂.