Experiment 6

How does a mixture of ashes and water differ from plain water?

Picture of little girl holding test tube.Materials:

2 or more laxative pills that have phenolphthalein in them. (Check the labels.)

Ashes — fireplace, coal, charcoal, trash, etc. (Try scrap paper ashes!)

1/2 Cup rubbing alcohol



Glass jar with lid

White bar soap

Baking soda



Other materials to test

Do this first:

1.    Crush laxative pills with back of teaspoon. Add alcohol.

2.    Leave the sediment in the saucer.

3.    Pour alcohol into glass jar.

Test the soap and other materials by adding a drop or two of the alcohol solution. Record any color change. A pink color means the solution is basic or alkaline. If the color stays the same, it’s acid.

Mix fireplace ashes with water and test with 1 or 2 drops of alcohol solution. Do the same with the other ashes, too. Which gives a stronger color change?

Try using ashes from other materials, too!


Make a testing solution with red cabbage and see what colors it produces in vinegar, baking soda, soap, etc.

Record the color changes and compare with the results of your earlier experiments.

Clue: Vinegar is an acid; see what color it becomes in your red cabbage solution. Test other materials. If they become the same color, they’re acids, too.

Can you find something that changes the red cabbage solution to a different color?