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Reaction Kinetics . Chapter 17A General Chemistry Mr. Mata. Standard 8b. Students will know how reaction rates depend on factors like concentration, temperature, & pressure. Essential Question:. What factors influence the reaction rate of a chemical reaction?. What is a Reaction Rate?.
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Reaction Kinetics Chapter 17A General Chemistry Mr. Mata
Standard 8b • Students will know how reaction rates depend on factors like concentration, temperature, & pressure.
Essential Question: • What factors influence the reaction rate of a chemical reaction?
What is a Reaction Rate? • Chemical kinetics = rates of reaction • Reactants disappear/products appear . • Reaction rate is fastest at the beginning of reaction and slows down as reactant concentrations decrease. • Three factors must be met for reactions to occur: • Collision frequency • Orientation • Activation energy (Ea)
Collision Theory • Collision frequency = rate @ which particles make contact with each other. • Key idea: molecules must collide with each other to react. • Successful collisions: • Collide with each other . • Have the correct orientation. • Have enough energy to break bonds.
Orientation Particle Orientation Required Orientation Unsuccessful Collisions Successful Collision
Activation Energy Activation Energy (Ea) Activation Energy (Ea) • minimum energy required for a chemical reaction to occur.
Ea Activation Energy (Ea) • Low Ea = instantaneous reaction • High Ea = slower reaction
Factors affecting Reaction Rate • Surface area • High surface area = fast reaction rate • More opportunities for collisions. • Increase surface area by… • Using smaller particles. • Dissolving in water.
Factors affecting Reaction Rate • Concentration • high concentration = fast reaction rate • more opportunities for collisions.
Factors affecting Reaction Rate • Temperature - High temperature = fast reaction rate • Higher kinetic energy • Faster moving particles. • More likely to reach activation energy. • Generally, rate of reaction doubles for each 10 C temperature increase.
Factors affecting Reaction Rate • Catalyst • substance that increases reaction rate without being consumed in the reaction. • lowers the activation energy.
Chapter 17 SUTW Prompt • Describe how temperature, concentration, and surface area affect chemical reaction rates. • Complete a 11 -12 sentence paragraph using the SUTW paragraph format. Hilight using green, yellow, and pink. • Due Date: Monday, March 19, 2018 at beginning of your regular class period.