Phthalein dye

Imagine you have a special color that can change when you mix it with different things. This special color is called a phthalein dye. It is like magic because it can tell us if something is acidic or basic.

To understand how this works, we need to know about acids and bases. Acids are things like lemon juice or vinegar. They taste sour and can be harmful if you drink or touch them. Bases are things like soap or baking soda. They feel slippery and taste bitter.

When we mix the phthalein dye with something that is neither acidic nor basic, it looks clear and doesn't change color. But when we mix it with an acidic substance, like lemon juice, it turns pink. This happens because the phthalein dye reacts with the acid and changes color. It's like a secret message that tells us it is acidic.

On the other hand, if we mix the phthalein dye with something that is basic, like soap, it turns blue or purple. The basic substance causes the phthalein dye to change color again. It's like another secret message that tells us it is basic.

So, the phthalein dye helps us figure out if something is acidic (pink) or basic (blue or purple). It's like having a special superpower to see if things are sour or slippery. Scientists and chemists use this dye to test how acidic or basic different substances are, which helps us understand more about our world.