Acid Reactions

One thing that acids do really well is to react with other chemicals. If you did the dirty-penny-in-cola experiment, you've already seen one such reaction, when the phosphoric acid in the cola removed the copper oxide coating from the penny. But the reaction itsefl wasn't very interesting while it was happening. Here are some acid reactions that are more exciting. They're kind of messy, but safe, as long as you follow the instructions carefully.

Acids really like to react with chemicals known as bases, which you can think of as "anti-acids" - they neutralize each other. You can collect some acids and some bases that you might have around your home, and observe their reactions.

What you'll need:
Small plastic cups
Eye dropper
Teaspoon
Mortar and pestle
Water
Marker
Newspaper or plastic sheeting
Household acids, such as vinegar, lemon juice, cola, aspirin, Vitamin C tablets
Baking soda (sodium hydrogen carbonate, which is a base)

First spread the newspaper or plastic sheeting around the area where you will be working because things may get messy! If you are using any acids in solid form, such as aspirin, grind them with the mortar and pestle and dissolve in water. Place a small amount of each acid into a plastic cup and label it. Add about half a teaspoon of baking soda to each acid, and stand back! What happens?

You should see a very fast and exciting reaction, with lots of foamy bubbles forming. These bubbles are filled with carbon dioxide, which is released by the reaction of the acid with baking soda. You might want to test other household acids to see if they have the same reaction.