Welcome To The Cyberlab Website
Cyberlab is a series of fun activities designed to get you excited
about science, to reinforce what you have learned in class, and to
stimulate critical thinking. Each activity will present a problem
or make a statement, your job will be to conduct an experiment, or make
a math calculation, and/or conduct research to solve the problem or
answer the question.
Some Watery Reactions!
Hi’ my name is Tonya. I am a middle school science student.
The other day our science teacher told us that water is called the
universal solvent,
that the human body is composed of 65% to 70% water. Water covers
over 70% of the Earth’s surface, and plants need water to grow. Then
he said something I never though about before, “without the presence
of water many chemical reactions would not take place!”
Prove the point my teacher placed a piece of aluminum foil
in a glass Petri dish. Next using a plastic spoon a greenish-blue chemical
was placed on the aluminum foil. The teacher asked the class was anything
was happening. We all laughed and said “no.” Much to my surprise I
was asked to come to the front of the lab. Putting on safety glasses
my teacher told me to use a medicine dropper and add a small amount
of water to the chemical.
The reaction was immediate and dramatic. Heat was given off
along with what appeared to be a white vapor producing reddish-brown
stuff in the Petri dish. When the reaction stop the aluminum foil had
a big hole in it!
Once again my teacher ask the class would this reaction taken
place if water was not added. This time you know what we all said!
Our teacher went on to tell us that the greenish chemical was called
copper chloride and the reddish-brown stuff was pure copper! A chemical
reaction had taken place in which mixing aluminum metal (foil) and
copper chloride when produced copper metal, but only if water was added.
Next we put our safety glasses on and our teacher gave all
us test tubes that contained a whitish-green chemical. The class was
asked what did we think would happen if water was added before anyone
could answer we were told to place the test tubes in the palm of our hands,
and with a medicine dropper add some water.
The affect was quite surprising, the chemical turned blue
in color, became very warm! Everyone in the class became excited. When
the excitement was over we were asked a series of questions for example,
where did the heat come from? What was the relationship between adding the
water and the release of heat?
I would like you to help me answer these questions by conducting
a series of hands-on experiments and emailing me your results. First,
the chemical used in both activities was copper chloride, which has
water bonded or connected to it. Click on this link to the cyberlab lab
sheet where you will find the direction needed to perform
the experiments.
Internet connection
It is common to find water chemically bonded to many naturally occurring
compounds, forming hydrates of those compounds.
This is especially true of crystalline
solids. When heat is added the water is released forming a dehydrated
solid.
When you have finished conducting this activity send a brief email summary
of your results to the other participating science classes. Hopefully they
will be able to reproduce your results. To send an email click on the "Post
Results" icon. (NOTE: when posting results over
the Internet do not write your last name! - safety precaution)
Post Results
This activity was developed by Mike Calhoun and sponsored
by Science
In A Bag.com.
Copyright © 2008 by Michael J. Calhoun. All rights reserved