Are Household Powders Acids or Bases?
Talk It Over
Many everyday substances are either acids or bases. Orange juice, vinegar, and cola drinks are acids. Many cleaners, such as household ammonia, are bases. Some substances, called indicators, are one color in an acid and another color in a base. You can use them to tell acids and bases apart.
- 1-cup measuring cup
- Rubbing alcohol
- Measuring spoon
- Ground turmeric (from the spice aisle Rolling pin at the supermarket)
- Coffee filter
- Small jam jar
- 1 gallon distilled water (available in the laundry products aisle at the supermarket)
- Ziptop plastic sandwich bags
- Rolling pin
- Powders to test such as baking soda,baking powder, washing soda, salt, sugar,cream of tartar, chalk, Epsom salts, dishwasher powder, powder laundry detergent, borax, laundry soap, or pills such as calcium, vitamin C, antacids, or aspirin
- First, make an indicator from turmeric, following these steps:
- Measure ¼ cup of rubbing alcohol into the measuring cup.
- Add ¼ teaspoon ground turmeric.
- Stir well with a spoon.
- Put the sieve on top of the jar.
- Put the coffee filter in the sieve.
- Pour the alcohol/turmeric mixture through.
- When all the liquid has run through the coffee filter, remove the sieve and put the filter in the trash.
- Add ½ cup of distilled water to the alcohol/turmeric mixture in the jar. Stir.
- This is your turmeric indicator. It will turn an acid bright yellow. It will turn a base bright red.
- To test a powder, use a clean, dry spoon to put a small amount of the powder on a plate. Using the dropper, add a few drops of your turmeric indicator and note the color change, if any. (If the indicator remains pale yellow, the powder is neither an acid nor a base.)
- To test a pill, place it in a ziptop bag and roll with a rolling pin to crush it into a powder. Then test as in step 2.
Rubbing alcohol is poisonous and can hurt your eyes. Do not use rubbing alcohol without an adult's help. Some cleaning powders can burn your skin. Never put any of the materials used in this experiment in your mouth or eyes. If you get some on your skin, wash with water immediately.
The "Go" procedure will work for you. Try testing three powders: dishwasher powder, salt, and baking soda.
Turmeric isn't the only useful indicator you can make at home. Boil some red cabbage in a small amount of water and use it to test powders. Relating it to your turmeric data, you should be able to infer what its color changes show. Purple grape juice and the packing juice from canned blueberries are worth a try also. Read more in the following project about the pH scale and how it is used to measure acids and bases. If time permits, order some pH paper from a scientific supply house or borrow some from your school. Use it to check the conclusions you drew from your indicator experiments.