<<< previous Yes, vinegar turns the cabbage juice red again! You can try doing this with some other household liquids butask an adult which liquids you can use. What’s Happening? Red cabbage juice is sensitive to whether something is an acid or the opposite, an alkali. If you add acid to it, it goes red, add an alkali and it goes blue. You can use this to test whether household substances are acid or alkaline. When you add the water to the cabbage leaves in Norfolk, it turns blue because Norfolk water is hard water – it is very alkaline. In Cornwall, for example, the water is acid and known as soft water. There the cabbage water would stay red. If you added the vinegar first and then the bicarbonate of soda, you will have seen energetic fizzing. This is because the acid vinegar and the alkali bicarbonate react violently, giving off carbon dioxide. |