Editor’s note: This story is part of our MC faculty and staff series in which professors and/or staff discuss relevant topics within their areas of expertise. Frances Nolen is an instructional lab coordinator in Department of Chemical and Biological Sciences at the Germantown Campus.
Winter break means time with loved ones—and more time indoors. Having ideas for fun projects to do at home can come in handy, especially with kids in the house. Here are a couple of chemistry projects that can be safely done at home and produce beautiful results:
- Designer carnations
Have you ever seen a tri-colored carnation? You can easily make one with these ingredients:
- A white carnation with the bottom 2–4 inches sliced vertically (this part needs to be done by an adult using a sharp knife). The vertical slice has to be a little longer than the height of the cups, so shorter cups are better.
- Two colors of food dye (blue and yellow work well, but if you have several carnations, you can experiment with other color combinations.)
- Two paper or plastic cups with a few inches of water in each cup.
- You may need to make a support for the carnation. This could be a pencil taped to a Kleenex box (or some other sturdy support). Tie the carnation to the pencil with string. Another option is to use Scotch tape between the carnation and the cup.
Put five to 10 drops of food coloring in each cup with the water. Stir to distribute the food coloring. Position the carnation so one part of the stem is in each cup and the carnation is supported by the pencil. Leave overnight and check out the carnation colors in the morning. Pretty cool!
How does this work?
The science behind this experiment is capillary action. First, though, we need to picture the inside of the stem of the carnation. It looks like tiny straws that form tubes that go from the end of the stem to the flower, and even into the flower itself. When the flower was still on the carnation plant, these tubes extended all the way to the roots and allowed the carnation plant to feed itself water and nutrients from the soil.
Liquids are drawn into the tubes because the surface tension of the liquid (water, in this case) and the attraction of the water to the surface of the tubes is greater than the force of gravity pulling down on the water. The narrower the tube, the higher the water will rise.
Having ideas for fun projects to do at home can come in handy, especially with kids in the house
Water is not the only liquid that displays capillary action, but it has a high surface tension, so if the tubes are really narrow, the water can rise as high as 300 feet (sequoia trees are often 300 feet tall).
- Chromatography decorations
Did you know that black magic markers don’t just have black ink in them? The ink is actually a mixture of several colors that together make it appear black. In this experiment, you can make decorations that separate the colors in the “black” ink of magic markers to create unique designs. Here’s what you’ll need:
- A coffee filter or a paper towel cut into a circle or square about eight inches across
- A black or brown marker (you can try different brands or other felt-tip markers)
- An eye dropper*
- A smooth surface (like a countertop) covered with several layers of paper towels
Make several spots on the coffee filter or paper towel that are no bigger than ¼-inch (about the diameter of a pencil) using the magic marker. Slowly add several drops of water to each spot and watch the spot spread out through the coffee filter or paper towel. What colors can you see? Once you see how the color separation happens, you can create your own designs and make decorations for your home.
Tip: the editorial team did this experiment using both black and brown markers. The brown ink seemed to yield the best results.
How does this work?
The science behind this experiment is paper chromatography. Paper chromatography (that’s a mouthful, isn’t it?) is a technique that takes advantage of the fact that bigger molecules move slower than smaller molecules. The dyes that make up the ink in the marker pen have different chemical structures. Each chemical structure has a different mass, or weight. The smaller structures move faster (farther) and the bigger structures move more slowly (less far). From the places where the different colors ended up, can you figure out which dyes are made of smaller structures? Which dye had the largest structure?
Good luck, and have fun!