1. Define chemical equilibrium in terms of a reversible reaction.
2. Identify physical processes and chemical reactions that go to equilibrium and those that go to completion.
3. Describe Le Chatelier's Principle and predict changes in a chemical equilibrium system due to changes in (a) concentration, (b) temperature, (c) pressure and (d) the addition of a catalyst.
4. Explain the requirements in The Haber Process (or the Haber-Bosch process).
5. Describe the common-ion effect.
This is a brief explanation of equilibrium with a very clear animation:
I am including this explanation as well because it will be referred to in subsequent segments:
If the reactants or products leave the system, a reaction will continue to completion and eventually stop. This can occur when a gas leaves a system (sometime bubbles are formed) or when a solid precipitate settles out of a solution.
Le Chatelier's Principle explains shifts in the equilibrium system due to changes in concentration, temperature, pressure and the addition of a catalyst, and the eventual establishment of a new equilibrium. This all comes back to the idea of collision theory.
The following video continues with the previous explanation with the picture of digging and filling a hole:
Endothermic reactions absorb energy as a reactant (left side of the reaction), and delta H has a positive value.
Putting the energy in the reaction equation (simply as Q) makes it easier to predict the direction of the shift if you think of the heat (Q) similarly to a reactant or product.
One important application of Le Chatelier's principle is The Haber Process, explained in this video -- there's 1 minute of introductory credits (snore), but this clip continues right after that:
Another phenomenon is the Common Ion Effect -- the straight definition in textbooks can be confusing, so here is a short video with animation:
This uses the colored compound CoCl2:
This is a lab based on the acid-base indicator Methyl Orange:
A very simple demonstration is that of yeast being used as a catalyst to speed up the decomposition of hydrogen peroxide (H2O2) to produce water and gaseous oxygen -- if performed in a test tube, a glowing wooden splint (not flaming) will reignite when inserted into the gas. You might want to put an index card over the end of the test tube to trap the gas. DO NOT USE A STOPPER TO TRAP THE GAS! The gas pressure would build up and the stopper could shoot out, maybe into someone's eye!
Here are some worksheets regarding Le Chatelier's principle:
This worksheet contains multiple choice questions:
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Have a good end of the week!