Chemical Reactions Limiting Reagent

Stoichiometry A method of analyzing chemical equations Basic steps include Balanced chemical equation Identify start and end Convert start to mole (if needed) Mole ratio Convert end to needed unit

Limiting Reagent Another word for reactant is reagent A limiting reagent limits the amount of product that can be formed in a reaction Unless substances are combined in exact amounts according to the balanced equation, there will usually be a limiting reagent and a reagent in excess Watch this video for an example.

Finding the Limiting Reagent Predict amount of product formed based on amount of each reagent put into reaction. (2 stoichiometry conversions!) Identify limiting reagent (the reagent that give gives you less product) The other reagent is the excess reagent

How Much Excess? Once excess reagent is determined… Complete another stoichiometric conversion Limiting reagent →excess reagent (amount used) Subtract amount used from original amount of excess put into reaction The difference is the amount of excess reagent

Percent Yield If you actually do the lab and isolate a product, you can determine a % yield %𝑦𝑖𝑒𝑙𝑑= 𝑎𝑐𝑡𝑢𝑎𝑙 𝑦𝑖𝑒𝑙𝑑 𝑡ℎ𝑒𝑜𝑟𝑒𝑡𝑖𝑐𝑎𝑙 𝑦𝑖𝑒𝑙𝑑 x 100%