Turmeric is a brilliant spice, and it can be useful to help occupy any little scientists that you might have at home. Thanks to its unique chemical makeup, turmeric can be used to identify the rough pH value of a substance, making a fun little experiment that might be very handy in these turbulent times.
Doing The Experiment
This experiment is particularly simple, but the fun for a student can lie in picking out what they want to test with their indicator, rather than making up a batch of it.
To get started, an adult will need to make a batch of the indicator. They will need to mix a quarter of a cup of rubbing alcohol with a quarter of a teaspoon of turmeric powder. Then, proceed to give that mixture a thorough stir until the turmeric is completely dissolved. If rubbing alcohol is a little hard to come by, then you could use water. The only problem there is that it may take a little longer to completely dissolve the turmeric into the solution.
When the indicator is ready, you can ask your little scientists to collect a few household chemicals that they might want to test. Some good choices would be soap, vinegar, or baking soda.
Before the testing begins, make sure to ask the child what they think will happen. The indicator that you made earlier will change colour in the presence of bases, so if acids and bases are a topic that the student is currently studying, this may be a particularly well-timed activity.
The indicator should be a yellow colour before it has been used. This is because the pH of the indicator itself should be roughly neutral. When the indicator is added to acid (vinegar, for example), it will remain yellow. However, when it is added to a base (dissolved baking powder), it will turn bright red!
If the children carrying out the activity are up to date on knowing which chemicals are acidic and which are basic, you could make the activity a little harder. Try challenging them to find three chemicals that are acidic or neutral and three that are basic. The colour difference will be obvious, and this activity can help to develop scientific critical thinking abilities.
Children typically begin to study acids and bases at the time that they’d start high school, so at roughly eleven years old. Therefore, that might be the ideal time to do this activity with them. They would have enough context from science lessons to understand the experiment, but not quite enough for it to be too simple.