Everyday Products and Compounds
Date: October 2006
I am studying elements and compounds with my fourth
grade class. They are very interested in the chemical compounds
for different items. I am hoping to meet their enthusiasm with
some interesting information that they can relate to.
Can you send me some chemical formulas for some common household
items? For example cleaning products, fingernail polish, various
foods, simple plastics. Perhaps there are others.
Thanks for being so enthusiastic of a teacher! It's truly rewarding
to entice kids to want to learn more about chemistry. Of course, I
say that being a geeky chemist, so take that for what it is worth
;) Anyway, here is a list of things that I could come up
with. Note that when I list an item, I am primarily listing its
main or active ingredient. Thinks like Drain cleaner are mostly
water, but the active ingredient is sodium hydroxide, so I will list
it as sodium hydroxide and not water. So it will be important to
note to your kids that there are usually many chemicals in any one
product but only one or two give the product its main effect.
Drain cleaner - Sodium Hydroxide - NaOH (careful, this is of course
a dangerous chemical)
Mouthwash - Ethanol/Ethyl Alcohol - EtOH or CH3CH2OH (you may or may
not want to teach them this one)
Glass cleaner/Rubbing alcohol - Isopropanol/Isopropyl Alcohol -
iPrOH or (CH3)2CHOH (this means that the two methyl groups are
branched off of the CH group)
Ammonia - NH3 (gas dissolved in water, very corrosive)
Bleach - Sodium Hypochlorite - NaOCl
Table Salt - Sodium Chloride - NaCl
Sugar - Sucrose, which is two molecules of glucose put together -
Vinegar - Acetic Acid - AcOH or CH3(C=O)OH or CH3COOH
Baking Soda - Sodium Bicarbonate - NaHCO3
You can combine vinegar and baking soda to make a volcano!
Fingernail polish has had a lot of different chemicals in it over
the years and has been changed due to health and safety of the
solvents used, so I will not get into this.
There are many plastics, which are all polymers and include long
repeating chains of the given formulas. This may or may not be too
complicated for your class without a lot of further explanation.
Polyethylene (-CH2CH2-)n, where n determines how long the chain is
and also the properties of the plastic.
Teflon (PTFE) - polytetrafluoroethylene) (-CF2CF2-)n-(-CF2CF(OCF3))m
look here for a structure if you cannot read
Antifreeze/coolant - Ethylene glycol - HOCH2CH2OH
Gasoline and oil are too complicated of mixtures to explain, same
with most detergents and soaps
Foods are usually too complicated too, but the minerals: zinc (Zn),
magnesium (Mg), maganese (Mn), etc. are usually ions of the main
elements. Vitamins are very structurally complex.
I hope that I have put enough things down here so that there are
enough simple ones and enough complex ones so that they learn a good
amount and are not left wanting for more! Good luck,
Most household items are mixtures of several ingredients, which
makes things a little more difficult, but there are some items that
are relatively "pure" and "safe" for the 4-5 grade level. Common
table salt is sodium chloride (NaCl) if you are getting into the
shorthand symbols for elements, which is not a bad idea if you
limit it to a few simpler ones. There is sugar, which is common
enough, but has a much more complicated formula:
C12H22O11 (see http://en.wikipedia.org/wiki/Sucrose) for how the
atoms are put together. A simple example is aluminum (Al) as in
aluminum foil. Baking soda (NaHCO3) is sodium hydrogen carbonate
(common name sodium bicarbonate). Vinegar (plain white) is a 3%
solution of acetic acid (CH3CO2H). This works well with baking soda
because is "fizzes" CO2 when you mix the two -- and the reaction is harmless.
The labels on most household products have the ingredients
listed on the side. You might be able to do some "label" detective
work by looking for a particular substance in various household
products without actually doing any experiments. The advantages
here are: 1. ease of lesson preparation and 2. safety. 3. the wide
range of products and ingredients that would be available.
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Update: June 2012