Limiting Reagent Chemistry 11

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?

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

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

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

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?

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

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

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