Science Buddies: "Ask an Expert"

I need to monitor the effects of Le Chatelier on an experiment that i can easily do at home?? I dont know what experiment to use! Please Help!

Hi,

I understand you to be asking about Le Chateliers Principle. Here is a Wikipedia article on the French chemist:

http://en.wikipedia.org/wiki/Henri_Louis_Le_Chatelier

Here are lab experiments demonstrating the principle:

http://bouman.chem.georgetown.edu/S02/lect8/lect8.htm

http://www.digipac.ca/chemical/equilibr ... edurep.htm

http://www.saskschools.ca/curr_content/ ... elier.html

http://chemistry.olivet.edu/classes/che ... %20Lab.PDF

http://www.capital.net/com/vcl/equil/equil.htm

http://www.chm.davidson.edu/vce/equilib ... elier.html

http://www.kbcc.cuny.edu/academicDepart ... telier.pdf

http://dwb4.unl.edu/chemistry/smallscale/SS059.html

These experiments should give you enough information to understand the general idea of the type of experiment that you need to devise. Some possible home based experiments that come to mind:

1. Pick an acid base indicator that you have access to and experiment with the color changes on adding acid(like vinegar) or base(like household ammonia) to a solution of them. You can make an acid base indicator by boiling red cabbage
http://www.practicalchemistry.org/exper ... 58,EX.html

or you could use phenolphthalein( a laxative often available over the counter in drugstores), or a pH indicator (buy as test solution used to test pH of water in pools, from pool supply stores or some supermarkets).

2. You could investigate the solubility of salt (sodium chloride) in water and the effect of adding HCl (hydrochloric acid) to saturated solutions of it.

3. You could investigate the change of solubility in water of potassium nitrate, sodium sulphate and sodium chloride from about 30 to 100 C, and explain the differences observed and why. Check out the heats of solution of these salts to find the reason.

4. One of my favorite demonstrations is to have two bulbs connected by a tube. The two bulbs are about half filled with a solution of ammonia in water. If you warm one bulb with your hand the solution is forced out of that bulb into the other one. Why?

I hope this gives you some ideas. Lechateliers principle can be demonstrated in a zillion different ways.

Best of luck finding one that works for you,
Barrett L Tomlinson