Activation Energy.

Slides:

Advertisements

Similar presentations

kinetic vs. potential energy diagrams

Advertisements

Ch. 16 – Reaction Energy and Reaction Kinetics

Reaction Rates What affects the rate of reaction?.

Activation Energy and Catalyst. Temperature and Rate Generally, as temperature increases, so does the reaction rate. This is because k is temperature.

Section 2.8—Speeding Up A Reaction

The Collision Theory and Activation Energy Explaining how and why factors affect reaction rates.

Section 2.8—Speeding Up A Reaction

Kinetics: Reaction Rates and Potential Energy Diagrams

Reaction Rates Collision Theory  In order for reactions to occur, particles must collide  If collisions are too gentle, no reaction occurs  If collisions.

KINETICS How Fast Does A Reaction Occur? Energy Diagrams l Reactants always start a reaction so they are on the left side of the diagram. Reactants l.

KINETICS How Fast Does A Reaction Occur? Energy Diagrams l Reactants always start a reaction so they are on the left side of the diagram. Reactants l.

6.3.  Why does the rate of a reaction increase with Increased concentration of reactants Increased temperature Increased surface area.

Potential Energy Diagrams

Chemical Reactions Energy and Reaction Rates.  Chemical reactions require energy to start  Activation Energy - Energy needed to start a chemical reaction.

Chapter 16 Equilibrium. How do chemical reactions occur? Collision Model Molecules react by colliding into one another. – This explains why reactions.

Chemical Kinetics. Collision Theory of Reactions Collision theory is simple - for a reaction to occur, particles must collide successfully! A successful.

Collision Theory. Use the Collision Theory to explain the rate of chemical reactions. Include: Activation energy Draw potential energy diagrams for various.

Thermodynamics Tells if a reaction will occur. Kinetics Tells how fast a reaction will occur.

U1 S1 L2 Energy Diagrams MHR: Questions:. Upon completion of this lesson, you will be able to: define activation energy, activated complex, and heat of.

RATES OF REACTION. Rates of Reaction The rate of a chemical reaction is the speed at which the reaction occurs (i.e. speed at which the reactants are.

Chemical Rxn Rates. Chemical Kinetics The area of chemistry that concerns reaction rates. However, only a small fraction of collisions produces a reaction.

Explaining Reaction Rates Chapter 6.3. Explaining Reaction Rates We will further explain the factors affecting reaction rate with respect to Collision.

Explaining Reaction Rates

© 2009, Prentice-Hall, Inc. Temperature and Rate Generally, as temperature increases, so does the reaction rate. This is because k is temperature dependent.

Unit 11 Review Created by Mrs. Martin. 1. List the 6 factors that affect the rate of a reaction.

MiniUnit ~ Kinetics (Chapter 17) And you. Chemical kinetics is the study of the rates of reactions, how fast or slow a reaction occurs. By understanding,

How do reactions occur? Must have an effective collision between reacting particles for reaction to occur. “Collision Theory” Collision must be energetic.

The Collision Model The reaction rate depends on: collision frequency

What is a catalyst and what can they be used for?

UNIT 3: Energy Changes and Rates of Reaction

Chemical Kinetics PE Curves Mr. Shields Regents Chemistry U13 L06.

Chemical Kinetics Kinetics – how fast does a reaction proceed?

Section 2.8—Speeding Up A Reaction

Chemical Kinetics The rate or speed of chemical reactions - experimental & graphical How to control or influence the rate - faster or slower The mechanism.

UNIT KINETICS CROWE2009.

Unit 5: Thermochemistry

3.7 Energy Distribution Distribution Graphs

The Collision Theory and Activation Energy

Energy Profiles of Reactions

Graphing ∆H Chapter 5 P

Collision Theory.

Heat and Endothermic and Exothermic Reactions

Collision Theory: How reactions takes place

Second-Order Processes

DO NOW Get out Reaction Mechanism Practice. Pick up review.

Energetics & Rates GCSE REVISION.

Unit 8- Chemical Kinetics

A model for chemical kinetics

Rates of Chemical Reactions

Collision Theory.

KINETICS CONTINUED.

Thermodynamics.

7.3 Chemical Kinetics Objectives 3 and 4

ENERGY & CHEMICAL CHANGE

Ch. 16 – Reaction Energy and Reaction Kinetics

Temperature and Rate The Collision Model

CHEM 3310 Chemical Kinetics Collision Theory & Transition State Theory.

Ch. 16 – Reaction Energy and Reaction Kinetics

Collision Theory & Factors Affecting Reaction Rate

What is a catalyst and what can they be used for?

Potential Energy Diagrams

Rate Affecting Factors

Collision Model Goal: develop a model that explains why rates of reactions increase as concentration and temperature increases. The collision model: in.

Unit 4: Kinetics Collision Theory.

Bell Work: Kinetics Intro

Section 2.8—Speeding Up A Reaction

Second-Order Processes

MiniUnit ~ Kinetics (Chapter 17)

This is an endothermic reaction

Potential Energy Diagrams

Presentation transcript:

Activation Energy

Temperature and Rate of Reactions For a chemical reaction to occur, molecules must undergo effective collisions with the necessary energy (called the activation energy) for the reaction to take place.

Temperature and Rate of Reactions The following energy diagrams show an exothermic and an endothermic reaction. The “energy hill” represent the activation energy (Ea). The higher the activation energy, the slower the reaction, conversely, the lower the activation energy, the faster the reaction. At the top of the “energy hill” is the transition state where bond breaking and bond forming is taking place.

Temperature and Reaction Rate Several factor affect the energy of activation. However, in this section will focus on how temperature affects the energy of activation, which in turn affects the rate of the reaction. The Maxwell-Boltzman distribution curve shows the effect of temperature on the kinetic energy of molecules. When the temperature increases, the average speed of molecules increases and the number of molecules with KE greater than Ea also increase. This means that there will be an increase in the number of effective collision. It is the increase in the number of effective collisions that is mainly responsible for the increase in the reaction rate as the temperature is increased.

Arrhenius Equation

Using the Arrhenius equation to calculate the activation energy If we take the natural logarithm of both sides of the Arrhenius equation, we find that: