Aluminum Foil and Cupric Chloride Labette

The reaction between cupric chloride solution and aluminum foil is a very quick and simple labette to introduce a variety of topics in chemistry.

The reaction provides a very distinct set of observations that allow students to understand evidence that shows a chemical reaction is taking place.  The reaction gives off heat (exothermic reactions), obvious color changes, release of gas (bubbling and condensation), deterioration of the aluminum as it recombines.

The chemical activity is quite unique as there are several reactions taking place.   First the cupric chloride ionizes in the water producing the nice blue color from the copper inons in solution. Most aluminum foil has a layer of aluminum dioxide which reacts with chloride ion to liberate the oxygen and create aluminum chloride. The copper ion reacts with water to form copper hydroxide and release hydrogen. The bubbling is caused by the both hydrogen and oxygen gas which recombine to condense on the cooler surface of the mouth of the test tube. 

I have the students complete this labette multiple times throughout the year as a common thread tying together many different topics in the chemistry curriculum.

Goldfish Tails and Circulation

To witness blood flow in arterioles, venules and capillaries, my students view the transparent tails of living goldfish under the microscope.

We use medium size feeder fish for this lab.  Students create a bed of wet gause on half of a petri dish.  Situating the goldfish with the tail off of the gause, students weigh down the goldfish with a wet blanket of gause. The goldfish tail is then flattened using a half piece of a microscope slide. The students will then view the tail of the goldfish under the microscope to view the blood flow through the circulatory system of the goldfish.

Students can distinguish between blood flow in arteries and veins.  With a little patience and effective microscopy skills they can determine the heart rate of the fish by counting the pauses in the blood flow through the venules.  Most importantly students can witness cell movement through the capillaries as single cells line up and flow through the capillaries for diffusion between the tissues.

 Students took this video utilizing a Flip cam through the ocular of the microscope.