Invisible Paint
Objective:
Many common foods like vinegar and lemon have a sour taste and are called acids. Other foods like milk and baking soda are called bases. These foods and many other substances have different chemical makeups that make them either an acid or a base. Grape juice is an acid/base indicator. This means that it will determine the acid/base level of a substance by changing color. When grape juice touches the baking soda painting, the painting changes from clear to blue-green indicating that baking soda is a base.
Age Level:
Kindergarten – Second Grade
Materials:
· Cups
· 4 Tablespoons baking soda
· 4 Tablespoons water
· Cotton swabs
· Sheet of white paper
· Purple grape juice
· Clean paint brush
Art Experiment:
1. To make the paint, dissolve 4 Tbs. of baking soda in 4 Tablespoons of water in a cup.
2. Dip the cotton swab in the paint mixture and make a picture on the white paper.
3. Let the watery picture dry completely.
4. Next, brush grape juice over the paper to reveal the painting. The picture mysteriously appears in blue-green colors.