Chapter 17 Section 2 Reaction Rate p Reaction Kinetics Chapter 17 Modern Chemistry Sections 1 & 2 The Reaction Process Reaction Rate

Chapter 17 Section 2 Reaction Rate p Reaction Rate Section 17.2

Chapter 17 Section 2 Reaction Rate p Chemical Kinetics: The area of chemistry that is concerned with reaction rates and reaction mechanisms. The change in concentration of a reactant (or a product) per unit time as a reaction proceeds is called the reaction rate. Rate of Reaction -  [reactant a]  time  [product b]  time or

Chapter 17 Section 2 Reaction Rate p Any change in reaction conditions that affects the collision frequency, the collision efficiency, or the collision energy affects the reaction rate. IF COLLISIONS ARE INCREASE, THE RATE WILL INCREASE. Rate of Reaction

Chapter 17 Section 2 Reaction Rate p  Nature of Reactants  Temperature  Surface Area  Concentration  Catalyst Rate Influencing Factors

Chapter 17 Section 2 Reaction Rate p An increase in temperature increases the average kinetic energy of the particles. This increases the number of collisions and the energy of collision. To be effective, the energy of the collisions must be equal to or greater than the activation energy. At higher temperatures, more particles possess enough energy to form the activated complex.Temperature

Chapter 17 Section 2 Reaction Rate p Plop, Plop Fizz, Fizz

Chapter 17 Section 2 Reaction Rate p Breaking and making bonds cause a reaction. So…. Reaction rate is dependant on the type of bond and the molecule it’s in. It cannot be adjusted to improve reaction rate. Nature of Reactants

Chapter 17 Section 2 Reaction Rate p In heterogeneous reactions, the reaction rate depends on the area of contact of the reaction substances. An increase in surface area, increases the rate of heterogeneous reactions. Surface Area

Chapter 17 Section 2 Reaction Rate p To increase surface area, break the substance up into smaller pieces. Surface Area

Chapter 17 Section 2 Reaction Rate p Lycopodium Powder Explosion

Chapter 17 Section 2 Reaction Rate p Increasing the concentration increases the number of collisions. As the number of molecules in the system increases, so does the total number of possible collisions between them. If the number of effective collisions increases, the rate increases.Concentration

Chapter 17 Section 2 Reaction Rate p Gummy Bear Sacrifice

Chapter 17 Section 2 Reaction Rate p Catalysts

Chapter 17 Section 2 Reaction Rate p A catalyst is a substance that changes the rate of a chemical reaction without itself being permanently consumed. How a Catalyst Works provides an alternative energy pathway or reaction mechanism may form an alternative activated complex that requires a lower activation energyCatalyst

Chapter 17 Section 2 Reaction Rate p p. 571 H 2 O 2 Catalysts notes

Chapter 17 Section 2 Reaction Rate p A catalyst is not included as a reactant or product – it is written above the arrow. Two Types of Catalysts Homogeneous Catalyst- A catalyst that is in the same phase as all the reactants and products in a reaction system. Heterogeneous Catalyst – A catalyst in a different form than that of the reactantsCatalyst

Chapter 17 Section 2 Reaction Rate p Types of Catalyst

Chapter 17 Section 2 Reaction Rate p The Heterogeneous Catalytic Decomposition of Acetone

Chapter 17 Section 2 Reaction Rate p Ch 17 Sec 2 Homework Ch 17 Review Sheet

Chapter 17 Section 2 Reaction Rate p Ch 17 Sec 2 Homework Prepare for Rate of a Chemical Reaction Lab on page 586

Chapter 17 Section 2 Reaction Rate p Movies Insert Holt: Visualizing Matter Disc 2 TEMPERATURESURFACE AREA DECREASING RATE CONTACT OF REACTANTS CONCENTRATION