| This article teaches kids about chemistry and | | | | chemical, just don't do it. (Skip the |
| is an excellent introduction to the totally | | | | peroxide and cold pack if you have small |
| fun activities in homeschool chemistry | | | | kids.) |
| (including exothermic reactions, phase | | | | |
| shifts, and acid indicators). It's also good | | | | What about the red cabbage? Red cabbage juice |
| for boy scouts working on a badge, or for any | | | | has anthocyanin, which makes it an excellent |
| kids that love science experiments. These | | | | indicator for these experiments. Anthocyanin |
| experiments are part of a homeschool science | | | | is what gives leaves, stems, fruits, and |
| program that I teach, and I promise your kids | | | | flowers their colors. Did you know that |
| will love it. | | | | certain flowers like hydrangeas turn blue in |
| | | | acidic soil and turn pink when transplanted |
| Chemistry is an exciting subject for kids of | | | | to a basic soil? This next step of the |
| any age, especially if you set up a natural | | | | experiment will help you understand why. |
| discovery environment for them to safely | | | | You'll need to get the anthocyanin out of the |
| explore in. Let's find out how to do this | | | | cabbage and into a more useful form, as a |
| with your own homeschool science learning | | | | liquid "indicator". |
| environment. At a university, one of the | | | | |
| first things you will learn about in your | | | | Prepare the indicator by coarsely chopping |
| chemistry class is the difference between | | | | the head of red cabbage and boiling the |
| physical and chemical changes. An example of | | | | pieces for five minutes on the stove in a pot |
| a physical change happens when you change the | | | | full of water. Carefully strain out all the |
| shape of an object, like wadding up a piece | | | | pieces (use a fine mesh strainer) and the |
| of paper. If you light the paper wad on | | | | reserved liquid is your indicator (it should |
| fire, you now have a chemical change. You are | | | | be purple). |
| rearranging the atoms that used to be the | | | | |
| molecules that made up the paper into other | | | | When you add this indicator to different |
| molecules, such as carbon monoxide, carbon | | | | substances, you will see a color range: hot |
| dioxide, ash, and so forth. How can you | | | | pink, tangerine orange, sunshine yellow, |
| tell the difference between physical and | | | | emerald green, ocean blue, velvet purple, and |
| chemical changes? There's an easy way to tell | | | | everything in between. Test out the indicator |
| if you have a chemical change: if something | | | | by adding drops of cabbage juice to something |
| changes color, gives off light (like the | | | | acidic, such as lemon juice and see how |
| light sticks used around Halloween), heat is | | | | different the color is when you add indicator |
| absorbed (gets cold) or produces heat (gets | | | | to a base, like baking soda mixed with water. |
| warm). Some quick examples of physical | | | | |
| changes include tearing cloth, rolling dough, | | | | Have your indicator in a bottle by itself. |
| stretching rubber bands, eating a banana, or | | | | Old soy sauce bottles or other bottles with a |
| blowing bubbles. Shopping List: ? | | | | built-in regulator that keeps the pouring to |
| Rubbing alcohol (largest bottle) ? Hydrogen | | | | a drip is perfect. You can also use a bowl |
| peroxide (largest bottle) ? Baking soda | | | | with a bulb syringe, but cross-contamination |
| (largest box you can find) ? Distilled white | | | | is a problem. Or not - depending if you want |
| vinegar (largest size) ? Washing soda (near | | | | kids to see the effects of |
| the laundry soap) ? Citric acid (optional, | | | | cross-contamination during their experiments. |
| but nice to have) ? One head of red cabbage | | | | (The indicator bowl will continually turn |
| ? Clear ivory dish soap (small bottle) ? | | | | different colors throughout the experiment.) |
| Alum (check the spice section) ? Single-use | | | | |
| cold pack (not the gel kind) ? Plastic | | | | Your mission: To find the reactions that |
| zipper bags and old water bottles ? Muffin | | | | generate the most heat (exothermic), absorb |
| cup baking tray (12 cups or more) | | | | the most heat (endothermic), and which are |
| | | | the most impressive in their reaction (the |
| Let's mix up chemicals that bubble, ooze, | | | | ohhhh-ahhhhh factor). |
| freeze, and change colors. Before we start, | | | | |
| you'll need to get these items together: a | | | | The Experiment: Start mixing it up! When I |
| muffin cup baking tray, water, vinegar | | | | personally teach this class, let them have at |
| (acetic acid), baking soda (sodium | | | | all the chemicals at once (even the |
| bicarbonate), washing soda (sodium | | | | indicator), and of course, this leads to a |
| carbonate), rubbing alcohol, hydrogen | | | | chaotic mix of everything. When the chaos |
| peroxide, citric acid, ammonium chloride | | | | settles down, and they start asking good |
| (don't activate the cold pack, but instead | | | | questions, I reveal a second batch of |
| cut open and empty the contents into a | | | | chemicals they can use. (I have two |
| plastic bag and discard the water pouch | | | | identical sets of chemicals, knowing that the |
| inside), aluminum sulfate ("alum" in the | | | | first set will get used up very quickly.) |
| spice section of the grocery store or drug | | | | |
| store), a head of red cabbage and a clear | | | | Tip for Testing Chemical Reactions: |
| liquid dish soap such as Ivory. | | | | Periodically hold your hand under the muffin |
| | | | cups to test the temperature. |
| Cover your kitchen table with a plastic | | | | |
| tablecloth (if you have small kids, put | | | | After the initial burst of enthusiasm, your |
| another tablecloth on the floor to catch the | | | | homschool science students will intrinsically |
| spills). Place your chemicals on the table. | | | | start asking better questions. They will |
| A set of muffin cups make for an excellent | | | | want to know why their green goo is creeping |
| chemistry experiment lab. (Alternatively, you | | | | onto the floor while someone else just |
| can use empty plastic ice cube trays.) You | | | | bubbled up hot pink, seemingly mixed from the |
| will mix in these cups. Leave enough space | | | | same stuff. Give them the change to figure |
| in the cups for your chemicals to mix and | | | | out a more systematic approach, and ask if |
| bubble up - don't fill them all the way when | | | | they need help before you jump in to assist. |
| you do your experiments! | | | | |
| | | | Homeschool Science Teaching Tips: You can |
| Set out your liquid chemicals in easy-to-pour | | | | make this lab more advanced by adding a |
| containers, such as water bottles (be sure to | | | | postage scale (to measure the solids in exact |
| label them, as they all will look the same): | | | | measurements), small beakers and pipettes for |
| alcohol, hydrogen peroxide, water, acetic | | | | the liquid measurements, and data sheets to |
| acid, and dish soap (mixed with water). Set | | | | record temperature, reactivity, and acid/base |
| out small bowls (or zipper bags if you're | | | | indicator levels. Hint - make the data sheet |
| doing this with a crowd) of the powders with | | | | like a matrix, to be sure you get all the |
| "scoopers" made of the tops of your water | | | | possible combinations. |
| bottles. The small "scoopers" regulate the | | | | |
| amounts you need for a muffin-sized reaction. | | | | Use the indicator both before and after you |
| Label the powders, as they all look the | | | | mix up chemicals, and you will be surprised |
| same. | | | | and dazzled by the results! |
| | | | _____________________________________________ |
| Although these chemicals are not harmful to | | | | _______________ As a teacher, homeschool |
| your skin, they can cause your skin to dry | | | | science teacher, engineer and university |
| out and itch. Wear gloves (latex or similar) | | | | instructor Aurora Lipper has been helping |
| and eye protection (safety goggles), and if | | | | kids learn science for over a decade. |
| you're not sure about an experiment or | | | | |