Acids and Bases

12 January 2010 - Did you know if you take some purple cabbage and boil it with water (a few minutes in the  microwave) and save the juice you don't need those little papers that turn pink or purple for testing acids and bases.

 

So here we have diluted lemon juice on the left, water in the middle, baking soda in water and on the right is the purple cabbage juice.  Lemon juice is an acid and baking soda is a base so this should show which way the colors go.

As you can see, acids turn pinkish and bases turn bluish. It said to add just a couple of drops, but they came out pale so we added more drops of the cabbage juice to help the colors stand out more.  

 

We tried a few more liquids to see if they were acids or bases.  On the acid side was apple juice and vinegar.

 

Another base was dish soap.  the purple is water.

Here is the full color spectrum of the Ph testing.  Bases can be added to acids until the color reverses.  It is entertaining to watch and see what kind of concoctions you can make and what color they will be.