Color Change Violets Chemistry Demonstration


The color change violets project works because violets are natural pH indicators.

The color change violets project works because violets are natural pH indicators.

You can change violets from violet to green by exposing them to a household chemical. This is a fun chemistry demonstration, especially for the home.

Color Change Violet Materials

  • violets
  • household ammonia

Change the Color!

Really, nothing could be easier. Hold violets over ammonia and watch them change from blue or violet to green. You can speed the reaction if you use warmed ammonia or you can dip the flowers in the ammonia. The demo used to be performed as a sort of ‘trick’ using ammonia gas, which produces a quick and dramatic color change. With ordinary household ammonia, you can expect the color change to take a couple of minutes.

How It Works

Flowers, including violets, get their color from anthocyanins. This is a class of pigment molecules that changes color in response to pH. Ammonia is very basic, so it changes the blue color of violets to green. Violets come in other colors besides… well… violet, so expect a color change for these flowers too. The final color might not be green. For example, I tried this project using orange pansies (a form of violet) and got sort of a dull greenish-yellow color as a final result. Also, you can experiment with other flowers to get a color change in response to ammonia.

Learn More

Odor of Violets Chem Demo
Make a pH Rainbow Tube

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