Unit 1: Reaction Kinetics Lesson 3: More Factors Affecting Reaction Rates

Factors Affecting Reaction Rates 4) Nature of the Reactants Some reactions are naturally slower or faster than others due to the chemical properties of the reactants. These properties may include: the strength of the bonds involved (stronger bonds, slower reaction) the number of bonds that must be broken (more bonds to break, slower reaction) Demo 12.I.3, then notes – 10 min

Brain Break! 5 min

Factors Affecting Reaction Rates 5) Surface Area and Phase The greater the surface area of a reactant, the greater the ability of the reactants to meet, the more often collisions occur, and the faster the reaction. The phase of the reactants also affects the ability of the particles to meet, and the following trend is found: Demo 12.I.5, then notes – 10 min

Factors Affecting Reaction Rates 6) Catalysts and Inhibitors A catalyst is a chemical that increases the rate of a reaction but is not used up in the reaction. (We’ll look into how catalysts work later on.) An inhibitor is a chemical that reduces the rate of a reaction by combining with a catalyst or reactant in a way that prevents the reaction from occurring. Demo: Elephant’s Toothpaste, then notes – 10 min

Homework: Pg. 7 #10-11 Pg. 8 #13 Pg. 9 #16 Pg. 12 #20-22 15 min