Chemistry - Everywhere Around the House
- 2005 30 Mar
The laughter died down, John continued his tales of being a teenaged science geek. Again, he delighted everyone with stories of blowing up something in the basement and setting it on fire. Twenty years after the fact, it evokes laughter and John is an engineer for NASA developing new sub-space aircraft. To home educators, these stories bring trepidation about teaching laboratory science in general and chemistry in particular at home.
Chemistry textbooks are also fearsome, because they appear to be written in a foreign language. Often these books are written for science majors rather than for general science knowledge. And, our own understanding of the subject is discouraging. We were baffled in high school and we feel even more baffled now.
If the idea of a chemistry lab in your kitchen seems unrealistic, remember each time you cook a meal; you are applying principles of chemistry.
What Exactly is Chemistry?
Chemistry is the scientific study of the substances that make up the universe. Chemists investigate the characteristics of these substances, how they behave under different conditions, and seek to understand chemical changes. Basic chemistry, then, is about kinds of substances, composition, structure, properties, and interaction of material substances.
How Chemistry is Studied?
The chemist investigates. Meaning the study of chemistry is active and is best studied through experimentation. Most experimentation involves taking substances, making changes, and recording the reaction.
Experimentation, or testing, is used to prove statements that have been made about a substance. The statement iron will rust in water can be made. Then the statement is tested to be proven true or false. Many of the lab projects in high school chemistry books are these kinds of test.
Some statements are not practical to test. They just need to be accepted because of the expense or danger to test. Acceptance of science statements can lead to a discussion about faith in God. Not all things can be proven, but can be accepted.
Basic mathematics is necessary. Your student should know simple algebra and be familiar with the metric system. If you are using common household measurements, teach your student how to make conversions. Most chemistry books include a short chapter on these formulas. Study guides, such as Cliff Notes, will also have the formulas needed.
Chemistry Things Around the House
A medium-sized chemistry set purchased at a toy store will provide many of the items needed to teach a well-rounded chemistry course including chemicals required in your chem lab books. The chemicals are relatively safe when directions are followed. A lab book is generally included with sequential projects and can be the basis for a general chemistry course.
You will need a source of gas fire. Temperatures can’t be regulated with electric heat sources. Some experiments can be done on a regular gas-cooking stove.
You may be more comfortable with experiments that use a candle or micro-burner. In most case any small candle will work for a micro-burner. Micro-burners are available at school supply companies.
Any laboratory brings to mind test tubes, beakers, culture dishes, and graduated cylinders. That’s because chemicals should be mixed in glass utensils. Household glassware will often fill the bill.
Pyrex® custard dishes are great for growing cultures. Small juice glass can be used for mixing.
Test tubes are in the chemistry set purchased at a toy store.
A cooking thermometer works in most cases where temperature changes are being recorded. A glass Celsius thermometer will help your student begin thinking as a scientist.
Eye droppers are used to transfer small amounts of chemicals. I save glass dropper bottles that come with medication. Although these are getting harder to come by, you can ask a pharmacist.
Don't use plastic in the place of glass. First, glass is neutral and won’t react with the chemicals. Plastic gives off molecules that can alter the reaction of your experiment. Second, the chemical mixture can melt the plastic, making a mess to be cleaned up. Third, glass can be boiled to assure that you are using clean equipment.
Store all of your science glass items away from the kitchen. You don’t want to use a “culture” dish for pudding.
The very word “chemicals” can bring fear to the heart of the most stalwart home educator. Actually most chemicals used in high school labs are already in your home.
You don’t need to spend a lot of money or use anything that concerns you. If you look at a lab and are uncomfortable with what is used or the outcome, don't do it.
This list of chemicals, along with their common names, is taken from chemistry textbooks.
Sodium bicarbonate - baking soda
H4Al2Si2O9 - cement
Acetic acid (HC2H3O2) - vinegar
NH4OH - ammonia
H2O2 - hydrogen peroxide
Sodium chloride - salt
Citric acid - lemon juice
Sodium hydroxide - lye (Drano)
Carbon dioxide - soda pop
Magnesium hydroxide - milk of magnesium
Na4 B4 O7 - borax
Any of these chemicals can be purchased at drug stores or grocery stores.
Chemistry at Home
Careful reading of the instructions by you and your students is the starting point of chemistry labs. If expected results are given, you can assess any danger. Remember that it’s not necessary to do every experiment in the textbook.
Models illustrate the unseen. A model of an atom or molecule will teach the basic structure and demonstrate how atoms join together to form molecules. Or, some students prefer to draw the atoms and molecules.
To test how chemicals react, they need to be mixed. Mixtures can be made with items you have at home.
Remember the volcano that we built in elementary school? The lava flow can be the foundation for testing. We know mixing baking soda with vinegar makes the lava flow. Your student can test other concoctions to make a lava flow.
Begin by learning why baking soda and vinegar react the way they do. With this information, your student can make an educated guess, a hypothesis, about other chemicals that may react the same way.
My sons often used the “Let’s see what happens” method. They’d state a hypothesis such as “Cola mixed with baking soda will create a lava flow.” (Although not an educated guess, it was a guess.)
When this hypothesis didn’t work quite right, they then studied the vinegar and baking soda chemical reaction, including the chemical make-up of vinegar and cola. With this knowledge they were able change to “chemicals” that were similar to vinegar and test the reactions.
My boys learned the chemical make-up of various substances, how they react to each other and under what conditions, and some chemical formulas used to design further tests.
Some household chemicals mixtures can be dangerous, so only mix combinations that you know the outcome. For example: bleach and ammonia mixed create a poisonous gas.
Chemistry is an everyday science. With a little adventurous sprit, some common sense, and a few household items, you too can teach chemistry in your kitchen.
Susan K. Stewart is the author of Science in the Kitchen, Fearless Science for All Ages. She presents workshops on teaching science at home including high school lab sciences. Susan and her husband Bob began teaching their three children in 1981 graduating all of them from home school. She can be reached at firstname.lastname@example.org or visit her web site www.skstewart.com.