{ Equilibrium Learning Goal: Students will understand that many factors influence chemical reactions and some reactions can achieve a state of dynamic.

The idea that reactions occur during molecular collisions.Collision Model

TemperatureConcentrationSurface AreaPressure

Conditions That Affect Reaction Rates

Factors Affecting Rate Temperature Increasing temperature always increases the rate of a reaction. Surface Area Increasing surface area increases the rate of a reaction Concentration Increasing concentration USUALLY increases the rate of a reaction PressureIncreasing the pressure on a reaction involving reacting gases increases the rate of reaction. Changing the pressure on a reaction which involves only solids or liquids has no effect on the rate.

The minimum amount of energy needed for a reaction to occur.

Activation Energy

Activation EnergyThe minimum energy required to transform reactants into the activated complex (The minimum energy required to produce an effective collision)Flame, spark, high temperature, radiation are all sources of activation energy

A substance that speeds up a reaction without being consumed.Enzymes are catalyst inside the body.

Catalyst

Catalysts Increase the Number of Effective Collisions

The exact balance of two processes, one of which is opposite of the other.

Equilibrium

Chemical EquilibriumReversible Reactions: A chemical reaction in which the products can react to re-form the reactantsChemical Equilibrium: When the rate of the forward reaction equals the rate of the reverse reaction and the concentration of products and reactants remains unchanged2HgO(s) 2Hg(l) + O2(g) Arrows going both directions ( ) indicates equilibrium in a chemical equation

Ozone Production

Ozone Protection

Ozone DepletionThe reaction that breakdown the ozone layer is catalyzed by chlorine atoms.One chlorine atom can catalyze the destruction of about one million ozone molecules per second.

http://video.nationalgeographic.com/video/player/environment/global-warming-environment/global-warming-101.html#antarctica-ozone-vin

http://www.ted.com/talks/lang/eng/james_balog_time_lapse_proof_of_extreme_ice_loss.html

A dynamic state where the concentration of all reactants and products remain constant.

Chemical Equilibrium

Le Chateliers PrincipleWhen a system at equilibrium is placed under stress, the system will undergo a change in such a way as to relieve that stress.

When you take something away from a system at equilibrium, the system shifts in such a way as to replace what youve taken away.Le Chatelier Translated:When you add something to a system at equilibrium, the system shifts in such a way as to use up what youve added.

Le Chatelier Example #1A closed container of ice and water at equilibrium. The temperature is raised.Ice + Energy Water The equilibrium of the system shifts to the _______ to use up the added energy.right

LeChatelier Example #2A closed container of N2O4 and NO2 at equilibrium. NO2 is added to the container.N2O4 (g) + Energy 2 NO2 (g) The equilibrium of the system shifts to the _______ to use up the added NO2.left

LeChatelier Example #3A closed container of water and its vapor at equilibrium. Vapor is removed from the system.water + Energy vaporThe equilibrium of the system shifts to the _______ to replace the vapor.right

LeChatelier Example #4A closed container of N2O4 and NO2 at equilibrium. The pressure is increased.N2O4 (g) + Energy 2 NO2 (g) The equilibrium of the system shifts to the _______ to lower the pressure, because there are fewer moles of gas on that side of the equation.left