OnLine Lab: Le Chatelier's Principle

For this lab, you will visit a website that has 'before-and-after' pictures for many equilibrium systems.  The lab will involve choosing an equilibrium system, selecting a 'stress icon' to change the equilibrium in some way,' noting what visible changes occur in the test tube from the stress, and finally offering an explanation in terms of Le Chatelier's Principle for what was observed. .  In some cases, there are NOTES at the bottom of the screen that give you hints about what might happen--look for these.

You will write your observations and reasoning on a separate sheet to turn in.  Once you've made the prediction, you can click the icon of the 'stress item' to see if you were correct.

Click here to go to the experiment WEBSITE.

BEFORE YOU BEGIN your lab, click on the EXAMPLE and follow along.  In the example, you'll observe & explain the effects of adding substances to an equilibrium involving silver chloride. The example includes a MODEL FOR RECORDING YOUR OBSERVATIONS to turn in--follow this model when you start the actual lab.

Choose the following systems & stresses:

I.  Cobalt system 

Try ALL the stresses:  heating, cooling, adding three substances.  You can do them in any order. 

II.  Ammonium system

Try adding ammonium chloride and HCl.  (Omit the other one)

III. Iron thiocyanate system

Try all stresses

IV. Chromate system

Try both stresses

(OMIT systems V and VI.  Well, you can do them if you want, but you don't have to turn anything in for them.)

REMINDER:  You will TURN IN a sheet on which you've recorded all your observations & explanations, following the model from the example.