Lab: Acid or Base?

Our class did a science lesson on acids and bases. Acids are sour, and bases are bitter and sometimes slippery. We can use some stuff like red cabbage juice and litmus paper to measure acids and bases. If the litmus paper or some red cabbage juice turns a bluish purple color it is probably pH of neutral. If the color is like red, pinkish red, or purple it is probably a pH of an acid. If the color is like violet, green, and blue it is probably a pH of an base. Some examples for an acid are lemon juice, soft drinks, vinegar, tomato juice, and sour milk. Some examples for a base are soup, baking soda, plaster, cement, and some dyes. Also acids have high concentration of hydrogen ions, and bases have low concentration of hydrogen ions. Acid give up hydrogen ions (H+), and bases give up hydroxide ions (HO-). When the two react with each other, they neutralize each other.

On our project we used some red cabbage juice, and we had different kind of acid and bases. There were about 10- 20 items to test (of course not tasting it), and we used the red cabbage juice. We each had a piece of paper, and we had to write what the item was and predict if it's an acid or base, what the color is going to be, and if it's strong or weak. When we tested it turned to a color, and you had to record your onservations on your lab paper.