The new Cabbagindicator!

A new indicator! For kids!

A natural indicator!

The Cabbagindicator is a non-toxic substance and is fun to use! It is made of red cabbage juice. It's easy to make and have a wide range of colors. It's a good way to show your students that chemistry is in their day routine not just in the Chemistry class.

The Sci Guys: Science at Home - SE2 - EP4: Red Cabbage pH Indicator - Acid Base Indicator

How does it work?

For most pH indicators, the compound acquires a proton at low pH (lots of H+) but looses it at higher pH. This seemingly minor alteration is sufficient to alter the wavelengths of light reflected by the compound, thus creating the color change with respect to pH. Anthocyanins behave somewhat inversely in that the pigments "gain" an -OH at basic pH, but loose it at acidic pH.
An acidic solution contains an excess of protons or H+. pH is a measure of how 'acidic' a solution is. The lower the pH, the more acidic the solution. In chemical terms, pH means "the negative log of the concentration of protons" in solution.
Anthocyanins in Beverages

What is the color range?

Red cabbage contains a water-soluble pigment called anthocyanin that changes color when it is mixed with an acid or a base. It turns red in acid environments with a pH less than 7 and turns bluish-green in basic environments with a pH greater than 7.
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- Make sure to read the labels of the liquids you are going to test on. Sometimes you may think the product is basic but because of a substance they have, it might change the pH.

- Use substances that you are sure of its pH.

- Don't forget the safety procedures, use safety glasses.

- It would save more time, if you already have the red cabbage juice, before the experiment. So just buy the Cabbagindicator! It's cheap and already in the liquid form!

Guaranteed to be fun and educational!