Strange tea

Dark, brewed tea becomes clear


- 3 cups,
- spoon,
- knife,
- baking soda,
- lemon juice,
- brewed tee.


First brew a tee with your parents.

Than set on the table 3 cup - fill each with the same amount of brewed tea.

Do some lemon juice.

To the first add some lemon juice,

to the second -nothing, to the third add half tablespoon of baking soda.



The color of the first glass should change to amber - characterized by weak tea,

while in the third to the dark brown - characteristic of very strong tea.

Contained in tea tannin derivatives change color under the influence of pH. Addition of sodium bicarbonate (NaHCO3), which is easily hydrolyzed, as it is the salt of a weak acid and a strong base, increases the concentration of hydroxide ions (OH-) in solution and thus increases the pH. The addition of citric acid, which increase the concentration of dissociating hydrogen ions (H +) in the solution decreases the pH.