Equilibrium



__**Introduction**__

Until this point, most of you have been taught to write chemical equations like this REACTANTS --> PRODUCTS. This implies that, assuming the reaction proceeds, you will eventually have all products and no reactants. This is true of some reactions, but the products of many reactions will start to form reactants again as soon as they are formed. These reactions are known as __reversible reactions__ and these reactionsl can set up a system known as __chemical equilibrium__. That is just what this unit is all about.

__**Key Words**__

Reversible Reaction, Dynamic Equilibrium, Closed System, Forward/Reverse Reactions, Equilibrium Constant (Kc), Le Chatelier's Principle, Equilibrium Position, Haber Process, Homogenous Reaction

AHL - Liquid-Vapour Equilibrium, Vapour Pressure, Enthalpy of Vapourisation, Homogeneous Equilibrium, Heterogeneous Equilibrium

__**Equilibrium System**__


 * Introduction to Equilibrium**
 * Activity**: Go to here and find out some information about chemical equilibrium
 * What are the 4 characteristics of an equilibrium system?
 * In the laboratory, what do we observe when a system is in equilibrium?
 * What does the equilibrium graph show? Relate the graph to a chemical equilibrium system.
 * Find out what the symbol and meaning of the equilibrium constant is. Understand the equation.
 * Answer the questions at the bottom of this page.


 * Equilibrium Simulation**
 * Activity**: Go to here and work through the simulation on a simple equilibrium. Note: you must use Safari on Mac to see simulation.
 * Answer the questions on the page and the ones below
 * How does temperature affect the equilibrium constant (i.e. look at the equilibrium constants for (#2 and #5).
 * What does this change in the equilibrium constant mean?

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__**Le Chatelier's Principle**__


 * Le Chatelier's Simulation**
 * Activity**: Go to here to find 3 simulations (1-concentration, 1-pressure, 1-temperature)
 * Design 3 tables to collect information about these 3 reactions
 * Collect all the information when changing conditions of these equilibrium systems
 * Draw conclusions about the observations you have made
 * Relate these conclusions to Le Chatelier's Principle

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__**Haber Process - making ammonia**__ media type="youtube" key="c4BmmcuXMu8" height="315" width="420"

__**Liquid-Vapour Equilibrium (AHL Only)**__


 * Liquid-Vapour Equilibrium Animation**
 * Activity**: Go to here to get a basic animated explanation of this concept. The video below will also help. Use Firefox browser for Macs.
 * What is the equilibrium established? Describe it.
 * How is this equilibrium affected by temperature?
 * Relate what you have learned to your syllabus.

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__**Term 4/Holiday H/W**__


 * 1) Complete report on Reactions Rate IA (D, DCP, CE)
 * 2) Review and correct your Yearly Examination. Discuss your progress at home.
 * 3) Define all of the key words IN YOUR OWN WORDS. (**No cut-and-paste, please**)
 * 4) In your text book read the relevant sections on equilibrium and take notes __to address syllabus dot points__ in 8.1/8.2 and 6.1/6.2 (AHL only).
 * 5) Answer ALL text questions from these sections.
 * 6) Work through all of the activities on this page and watch the relevant videos. Add relevant information to your notes.
 * 7) You should be able to have an intelligent conversation about Equilibrium and have questions to ask at the start of Term 1, 2015.