Today Katie did a Chemistry workshop about acids and bases.
The experiment was really fun. Here is how you do it...
Instructions
1 Chop up half a red cabbage and leave it in a bowl covered with water for a bout 45 minutes. Drain off the water (it would have turned purple). Red cabbage water can be used as an indicator to test if something is an acid or a base. If it is an acid, the cabbage water will turn pink. If it is a base, the cabbage water will turn blue.
2. Using plastics cups, pour half a cup of cabbage water into each one - depending on how many substances you would like to test.
3. You can try a range of household items - vinegar, lemon juice, baking soda.
4. To get a TRUE test (because some items will not change the cabbage water), you can purchase litmus paper from a chemist. It costs about $7 for quite a few strips (and you only need a little piece to test each item). Litmus paper is used to test if a substance is an acid or a base and it changes colour according the the pH scale. Reds means ACID, Light Greens means NEUTRAL and Dark Green to Blue means BASE.
I tested backing soda. It turned... (see the photo below).
I got a piece of litmus paper then tested it. The litmus paper changed to dark green. When we matched it on the pH scale, it was an 8 so definitely a base.
If you would try this at home please leave a comment on my blog to tell me what color yours came out as.
Here are some pictures of mine.