1. Limiting Reagent
Chemistry 11

2. Limiting Reagent
When conducting chemical reactions, often one of the reactants will often limit the reaction
That is, one of the reacts will be depleted before the other(s)
For example, consider two burning candles
One is burning in the room
One is burning in a sealed jar
What is limiting each reaction?

3. Determining the Limiting Reagent
In many cases, the limiting reagent will be indentified:
i.e. propane burns in excess oxygen
However, there will be questions where the limiting reagent needs to be calculated
i.e. Lithium nitride reacts with water to form ammonia and lithium hydroxide. If 4.87g of lithium nitride reacts with 5.80g of water, find the limiting reagent

4. Determining the Limiting Reagent
Li3N + 3H2O  NH3 + 3LiOH
A B

5. Determining Limiting Reagent
For the mass of substance B, you will interpret the limiting reagent as follows:
Have more than you need – A limits
Have just as much as you need – neither limits
Have less than you need – B limits
If you continue with the question, all remaining calculations must be completed with the limiting reagent as substance A

6. Amount of Product?
White phosphorous (P4) reacts in oxygen gas to produce tetraphosphorous decaoxide. If 1.00g of white phosphorous is reacted with 13.8g of oxygen gas, how much tetraphosphorous decaoxide can be produced?

7. Amount of Product? L
P4 + 5O2  P4O10
A B

8. Amount of Product? L
P4 + 5O2  P4O10
A B

9. Practice Problems Limiting Reagent Product Section Review Page 131
23-26
Product
Page 134
27-30
Section Review
Page 135
1-7