3.4 Reacting quantities

• Stoichiometry: the relationship between the relative quantities of substances taking part in a reaction or forming a compound, typically a ratio of whole integers
• Atom economy is the ratio of the amount of useful product formed to the amount of reactants used in a reaction
• Atom economy = mass of desired product/total mass of all reactants x100
• A high atom economy is efficient and produce little waste products
• Sustainability favours reactions with high atom economy and low energy consumption
• Percentage yield is the actual yield of a product shown as a percentage of the theoretical yield
• % yield = (actual yield / theoretical yield) x 100
• Theoretical yield is the maximum possible amount of product that can be produced from a given quantity of limiting reagent
• Actual yield is the amount of product actually obtained when a reaction takes place under certain conditions
• Actual yield is measured experimentally, it may be less than or equal to the theoretical yield
• Factors that affect % yield include impurities, side reactions, unreacted starting materials, and loss of solvent