Rocket ScientistAcid Wizardry

 

What you need:

  • saucepan
  • water
  • blender
  • red cabbage
  • baking soda
  • vinegar
  • lemon juice
  • ammonia household cleaner
  • brewed coffee
  • soda
  • 6 glasses

starWhat do you do?

  1. Ask your parent to help boil red cabbage for 12 minutes. The water will turn blue. Let the water cool.
  2. Pour equal amounts of the blue juice into each of the glasses.
  3. Add a teaspoon of baking soda to one of the glasses. What color is the water?
  4. Add a teaspoon of vinegar to another glass. What color is the water?
  5. Repeat this process with each of the glasses using a different item.
  6. After the liquid has changed, try changing it back to its original color. Can you do it?
  7. Acids, like lemon juice or vinegar, are usually sour.
  8. Bases, like soap or baking soda, are usually bitter.
  9. Many acids or bases are poisonous so tasting them is not a safe way to determine if something is an acid or base. Instead, science wizards have come up with a safe test to determine if something is an acid or base. They use color-changing indicators to find out.
  10. Mixing acids or bases with something else can cause a chemical reaction.
  11. The cabbage contains a class of compounds called anthocyanins which change color with chemical reactions. It is an indicator (something that tells something about the substance it comes in contact with). When acids or bases are mixed with an indicator, the reaction causes the color change.
  12. The blue juice will turn pink with acids, and green in a base, and stay the same in a neutral (neither acid or base) substance.
  13. Adding a base to an acid will turn the color back to blue. It will neutralize (undo) the effect of the acid bringing the juice back to a neutral state.