Chromatography is used in chemistry to separate chemicals. For example, the pigments in leaves can be separated with alcohol and filter paper. The reason for the separation of colors in chromatography is that different chemicals dissolve at different rates and adhere with different amounts of force. We can learn a lot by testing with chromatography.
Deconstruct Black Ink
Your children can use chromatography to deconstruct black ink and find out what color the ink really is.
What You'll Need:
- Coffee filter paper
- Black water-soluble marker
How to Deconstruct Black Ink:
Step 1: Have your children cut a 1 x 4-inch strip from the coffee filter paper. With a marker, they should draw a person one inch above the bottom of the strip. Then have your kids hang the strip over the side of a glass so the drawing is in the glass.
Step 2: Ask your children to add just less than an inch of water to the glass. The drawing of the person should be above the water. And then everyone can watch what happens. The water rises up the filter paper and dissolves the ink from the marker. The water carries this ink up the filter paper, and the person stretches. As the water moves up the filter paper, colors appear as the ink is separated. Even though your kids might have thought black ink was just black ink, black ink is actually made of several colors.
Keep reading science projects for kids: chemical reactions for your kids to learn what chemical reaction creates rust.