Drill # 7 (4B) 4/24/13 List 5 factors that affect reaction rate: Nature of reactants Temperature Concentration Surface area Catalysts

Objectives SWBAT discuss 5 factors that affect reaction rates SWBAT determine whether a reaction is exothermic or endothermic based on a potential energy diagram. SWBAT identify activation energy and potential energy of reactants and products on a diagram.

Agenda Reaction Rate Inquiry Activity Notes on Reaction Rates & Energy in Chemical Reactions Questions and Worksheet

Factors that affect reaction rate: Nature of Reactants – different atoms, molecules, or compounds react with each other in certain ways (ex. Na reacts vigorously with water) Surface Area – two reactants must be in contact with each other to react. Gases and dissolved particles collide freely, so react faster.

Factors that affect reaction rate: Temperature – Increasing kinetic energy, increases motion & collisions. Also increases energy. Concentration – Increasing conc., increases collisions, so increases reaction rate Catalyst – lower the activation energy so that reaction has enough energy.

Reaction Rate

What is Reaction Rate? The change in concentration of reactants per time.

Collision Theory In order for a reaction to occur, there must be a COLLISION. Collision Theory provides two requirements for reactants to yield products: 1. Reaction needs enough energy 2. Colliding molecules must be oriented in a way to react

Drill – 6/14/11 1. What does each letter represent in the above energy diagram? 2. Is this reaction endothermic or exothermic?

Drill – 6/13 Use the following data to determine the rate law for the equation: 2X + Y  3XY Experiment [X] [Y] Rate (M/s) 1 0.10 0.20 1.40 2 0.30 12.6 3 0.40 5.60

Drill – 6/10/11 How would doubling the value of X affect the value of Y in each case. What about tripling? Y = X0 Y = X1 Y = X2 Y = X3