If hearing the word chemistry’ gives you visions of glass beakers ready to explode, be brave and read on. Understanding chemistry concepts is easier with active participation, but it doesn’t require fancy lab equipment. These chemistry experiments can be done safely in your kitchen and promise to be more fun than baking cookies.
Doing these simple experiments with your kids will teach both of you how interesting and fun physics can be.
Colors from coleus leaves
(The experiment requires adult supervision. You will be boiling alcohol which must be done on an electric stove or hot plate. Heating alcohol on a gas stove could cause the alcohol to burn.)
The leaves on a Coleus plant have red and green colors. This plant is available in most garden stores or florists.
Start by boiling the Coleus leaf in water for 10 minutes. Which color is removed from the leaf?
Remove the leaf, pour out the water, and add rubbing alcohol to the pan. Boil again. Now what color is removed from the Coleus leaf?
What do you know about the red pigment and green pigment? Some colors or chemicals dissolve in water. Others dissolve in alcohol.
This experiment shows that not all colors dissolve in water. The dyes that are used to color clothes do not dissolve in water. What do you think would happen if they did?
Make a copper-plated nail
Squeeze the juice of two lemons into a glass and add a pinch of salt. Put about 20 pennies in the bottom of the glass and let them stand for three minutes. Meanwhile, take a large clean nail and give it another good scrub with scouring powder and water. Put the nail into the glass and wait at least 15 minutes. When you take the nail out, it will be coated with copper.
Why? Copper from the pennies interacts with the acid of the lemon juice to form a new compound, copper citrate. When you put the nail into the solution, the compound plates the nail with a thin layer of copper that cannot be rubbed off.
Once kids see how much fun they can have with physics “tricks,” they will be eager to show their friends and continue learning about this amazing field of science.
Invisible ink
Mix a teaspoon of water with a tablespoon of flour in a sauce pan. When the mixture is smooth, dip a cotton swab into it and use it to write a message on a paper towel. When the message dries, it will be invisible.
When you are ready to read the message, use a clean swab to apply a few drops of iodine. Your message will appear in blue-black. To make the message disappear again, dab on a few drops of lemon juice.
What happened? The iodine reacts with the flour, a starch, to form a new compound that appears as blue-black. When you apply lemon juice, it react with the iodine to make a new colorless compound. Lemon juice will remove stains of iodine, ink, mildew, and rust from paper or cloth.
Exposing your children to scientific concepts while showing them that science can be fun, will stimulate their thinking and creativity. As you watch them develop an interest in science, you might find that you enjoy the experiments, too.
