Make your own pH indicator

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Make your own Ph Indicator with Red Cabbage


Red cabbage
Clear graduated cylinders or glasses
White paper
Apron or lab coat (avoid nasty stains!)
Test chemicals: Vinegar, Baking soda, Lemon juice, Washing soda, Laundry detergent, Soda pop, Alka-Seltzer
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Peel off six big cabbage leaves, tear them up into strips and put in a cup of warm water. Squish the leaves to get the juice out.
Depending on how much Red Cabbage Indicator you want to make use the optimum ratio of one cabbage leaf to two cups of water.
Pour the purplish cabbage liquid through a strainer to filter out all of the big chunks of cabbage. Doesn’t cabbage juice smell great? Save the liquid for the experiments to follow.
Set out three graduated cylinders or glasses, side by side. Fill each container half full with cabbage juice.
Since you know that vinegar is an example of an acid, add a little vinegar to the first glass of cabbage juice. Stir with a spoon and notice the color change to red, which indicates that vinegar is classified as an acid.
In the second glass add a teaspoon of washing soda or laundry detergent. Notice how the liquid turns green, indicating that this chemical is a base. Keep these two glasses of red and green liquid for future reference.
Try adding other “test chemicals" to a small amount of cabbage juice and note the color change to determine if the chemical is an acid or a base.
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  • Ph indicator
  • scientist

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