W15 Sour cherries and an opponent of acids


Acids are all substances that have a sour taste. In the previous experiment you have learned that citric acid and ascorbic acid have another property: They are  corrosive. Corrosive substances may damage your
eyes: Do not forget to wear GOGGLES! Ask an adult to be with you.
*  Take a 1-ml syringe, cut off the tip of the needle. * Suck  juice from a sour cherry into it.
* Left: Transfer micro drops  from the syringe on a white plastic surface: 1. One on the right side of the arrow, one on its left side.  2. Place 2 drops of lime water beside the left micro drop and 3.  two drops on the right micro drop.  4. Use a needle to mix the liquids on the right side
Observation: The colour turns from red to green. Right: Add 1 micro drop of vinegar (25 %) to the green solution. Mix:    The colour turns from green to red again when it is mixed with a micro drop of vinegar.
Remember: Lime water is an opponent of acids. Lime water makes red cherry juice green.
                        Vinegar is an opponent of lime water. Vinegar makes green juice red again.


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