Presentation on theme: "Limiting Reagent and Percent Yield. Always start with the balanced equation N 2 (g) + 3H 2 (g) → 2NH 3 (g) The mole ratio is 1:3:2 If we have 1 mole of."— Presentation transcript:
Always start with the balanced equation N 2 (g) + 3H 2 (g) → 2NH 3 (g) The mole ratio is 1:3:2 If we have 1 mole of N 2 and 6 moles of H 2 what is the limiting reagent? What is the excess reagent?
Excess reagent – the reactant that is present in more that he required amount for a complete reaction Limiting reagent – the reactant that is completely consumed in a chemical reaction
To solve these problems use the mole bridge Remember: – Only moles can cross – Specifically only the original mole can cross – And to cross you need to multiply or divide
4Fe + 3O 2 → 2Fe 2 O 3 0.75 mol of Iron react with 0.6 mol of oxygen to form iron(III)oxide. How many moles of iron(III)oxide form? You need a 1:1 comparison to decide who crosses! 0.75 mol0.60 mol X mol