EXPERIMENT 9: OBSERVATION OF CHEMICAL REACTIONS (by Lori Smith)

In this experiment we will investigate a set of reactions which can form precipitates (double replacement reactions), form a gas, form water (neutralization reaction) or do nothing at all. You will have a chance to actually see the reactions occur. Most important is learning to predict the products of the reaction based upon your obervations. There are a large number of reactions that you will perform so be organized in recording your observations. Be sure to carefully record the reactants so there is no room for error. It will be easy to get messed up if you are not organized. Each of you will be assigned a set of the reactions which you will have to write the balanced molecular, ionic and net ionic equation.

Be sure to check our Web Site for a discussion on how to write such equations.

On a future exam I will expect you to be able to use a solubility table to predict the products of any double replacement reaction I can image. I'll also expect you to be able to predict the products of any neutralization reaction of a common acid and base. Do not forget the gas producing reactions are among my favorite!

	PROCEDURE 1.  Perform the reactions one at a time in 13 x 100mm test tubes.  Add 15 drops of each solution into the test tube.  SAFETY CAUTION: The hydrochloric acid, sulfuric acid, potassium hydroxide, and sodium hydroxide solutions used in this lab are extremely corrosive to skin and clothing.  Be careful when using these reagents
	PROPER WASTE DISPOSAL: All solutions used in this lab may be safely rinsed down the sink with plenty of running water, except those which contain the silver cation, Ag+.  These solutions must be poured into the special waste container provided in the fume hood.
	2.  Mix the solutions together by firmly holding the top of the test tube in one hand and thumping the side of the tube near the bottom with the other hand.
	3.  Observe whether or not a reaction occurs.  Things to look for are precipitate formation (cloudiness or solid material dropping from the solution, . . .
	gas evolution (the solution begins to bubble), or . . .
	heat evolution (the test tube becomes extremely HOT!!!) (Note: It is difficult to depict HOT over the Internet!)
	4.  Record all of your observations into the RESULTS box under "Evidence of Reaction".  Use the following terminology; precipitate formed (include the color), gas evolved, heat evolved, or NR for no reaction observed.