Step 1 . write out a balanced reaction.
2H2 + O2 → 2H2O
Step 2 : Determine the mole proportion from the balanced equation.
From the balanced equation, we can see that :
- 1 mole of O2 gives : 2 mole H2O
- x mole O2 will give : 3.8 moles H2O.....(cross multiply)
∴ number of moles of oxygen required to give 3.8 moles of H2O
= 1/2 * 3.8 = x moles of O2
x = 1.9 moles
• This means that ,1.9moles of Oxygen ,will be needed to yield 3.8 moles of water.