top of page
Chemistry of Color
Instructions:
Supplies:

  1. Place a large dot in the middle of the coffee filter with a marker (or about 1 cm from the bottom of a newspaper/paper towel)

  2. Fold the coffee filter in half and then in half again

  3. Fill a cup of water about 1/2 cm up

  4. Place bottom point of coffee filter or bottom of newspaper/paper towel in water 

  5. Watch as colors disperse

  6. Take the coffee filter out and let it dry

What's Happening?

  • The colors separate due to the chemicals in the marker, the water, and the paper. 

  • Some colors attach to water better than others, so they move further through the paper because of their chemical size, weight, and shape. 

  • The different characteristics of each color allows us to see the colors separate! 

  1. Coffee filters (2) * or newspaper or paper towel

  2. Markers (Washable work best)

  3. Cup 

  4. Water

starting-in-cups.jpg
Why do we care?

  • Primary Colors: red, blue, yellow

    • Mixed together make up the other colors

  • Secondary Colors: made up of more than one color

 

Processed foods have chemicals added to them- some of them might be good and some might be bad. All of the chemicals have a unique pattern of colors associated with them. This technique of separating chemicals by color is called chromatography. Chromatography can be used to identify if the chemicals that are in the foods that are being produced have bad chemicals in them. 

circles-27975_1280.png
FURTHER EXPLORATIONS:

Do the activity above with these other materials and see what happens​​

​

  • SALTWATER: (additional supplies: salt)

    1. Put a tablespoon of water in a small cup and add ½ - teaspoon of salt. Swirl the cup until most or all of the salt dissolves

    2. Repeat normal instructions.

​​

  • LEAVES: (additional supplies: 2 cotton swabs, green food coloring)

    1. Gather leaves of different colors.

    2. Squish up the leaves. Can use mortar and pestle, or other kitchen tools. 

    3. Place leaves in a cup or jar.

    4. Add a few (2-4) tablespoons of rubbing alcohol to each jar.

      1. Option 1: allow the leaves to soak overnight to draw out pigment. 

      2. Option 2: place glass cups inside a pan of hot water to heat the alcohol. (maybe include a picture so this isn’t confusing)

    5. Place strips of your chosen chromatography paper in the cups with one end trailing out.

    6. Wait for 1-2 hours. It can also wait overnight.

    7. See the cool separation of colors!

​​

  • FOOD COLORING:  (additional supplies: crushed up leaves, rubbing alcohol)

    1. In a small plastic cup, add two drops of green food coloring

    2. Use a cotton swab to soak up the food coloring into one end of the swab

    3. Touch the cotton swab into the center of the coffee filter, making a dark green dot

    4. Place the dotted coffee filter on a cup, making sure that the dot is over the center of the cup

    5. Dip the other cotton swab in water, making it thoroughly wet

    6. Lay the cotton swab wet with water on top of the green dot on your coffee filter

    7. The color will spread out in a circle. You should be able to see a thin circle of blue on the outside and a thin circle of yellow on the inside!

bottom of page