“Reaction Rates” refers to HOW FAST A REACTION OCCURS

Factors that Influence Reaction Rates 1. Temperature  Examples: o Glow sticks in HOT water glow brighter than one in cold water o Antacid dissolves faster in HOT water than cold water

Factors that Influence Reaction Rates 2. Surface Area  Refers to how much of the outside of a substance is exposed to the environment  The greater surface area, the faster the reaction  Examples: o Lycopodium Powder o Headache medicine reacts faster in powder form than solid form (ex. Goodie Powder versus Tylenol Pill)

Factors that Influence Reaction Rates 3. Concentration  Refers to how much of a substance there is  The greater concentration of a reactant, the faster the reaction  Example: o Vinegar & Baking Soda in Beaker – more vinegar produces a faster reaction

Factors that Influence Reaction Rates 4. Presence of a Catalyst  Refers to a substance that speeds up a reaction but is NOT used up by the reaction  The catalyst can be recovered unchanged, and re- used indefinitely  Examples: o Yeast in our “chemiluminescent elephant’s toothpaste” reaction o Enzymes found in animals that speed up digestion

Factors that Influence Reaction Rates 5. Presence of an Inhibitor  Refers to something that slows down or stops a chemical reaction  Examples: o Why do we cover our left over foods? o Why do we even put food in the fridge? o Why do we use food preservatives like salts?

List 5 ways to make a reaction occur faster (increase the speed): 1. heat it up (increase temperature) 2. cut it up and make a powder (increase surface area) 3. add more reactant (increase concentration) 4. add a catalyst (ex. enzymes in digestion) 5. remove inhibitor (ex. take out of refrigerator, do not add preservatives like salt, lemon juice, “pickling”)

List 5 ways to make a reaction occur faster (decrease the speed): 1. decrease temperature 2. decrease surface area 3. decrease concentration 4. add an inhibitor (ex. Cover food and put in refrigerator; Add preservatives like salt, lemon juice, “pickling”) 5. remove catalyst (ex. do not add yeast to reaction)