The artistic side of science
Every day we experience chemical changes. Many of them occur in our kitchen: frying eggs, making cakes, cooking rice or baking a potato involves chemical reactions that result in the tastes, smells and textures of our food. But by washing our dishes and kitchen utensils we also trigger chemical reactions. The kitchen is a scientific laboratory!
Through this very colorful experiment you will discover the behavior of liquid dish soap on fats. All you need are 4 materials that you probably already have in your kitchen.
For this experiment you will need:
✔ A plate or container (a little deep)
✔ Food coloring (at least 3 different colors)
✔ Whole milk
✔ liquid dish soap
Pour the milk into the plate. Use enough to just cover the bottom. Next, add drops of different colored food coloring to the milk, leaving space between them. Now, add a drop of liquid soap on top of each drop of dye. Observe very carefully what happens. You’ll notice the dye sink in response to the liquid soap, then return to the surface.
This colorful chemical reaction is because the main function of detergent is to remove grease. Fat is usually in the dishes of the foods we eat, but it’s also found in whole milk.
Milk is an emulsion, which means it is primarily made up of water, but it also contains vitamins, minerals, protein, and small suspended droplets of fat. When we drop the liquid soap on the plate, it breaks down the fat in the milk. Doing so causes the colors to spread out and mix creating a rainbow of mesmerizing colors.
Variations: Repeat the experiment using skim or low-fat milk. Do you see the same rash in the colors?