 Acids, bases, and buffers. I'm sure you've heard those words before, especially water acids, and you've heard how dangerous they are. Well, actually bases are just as dangerous. Some things that you have around your house, like Drano, the clog remover, this is a very strong base. It's dangerous. If you get it on your hands, it's very slippery. A pretty weak base that you have you actually use in cooking is baking soda. Some acids, fruit juice, vinegar, bleach. These are very common acids you find at home. What I'd like for us to do is to use another household substance, which is red cabbage. A lot of natural dyes are in plant materials. If you take red cabbage and blend it with some regular rubbing alcohol, you make a good acid base indicator. So what I'm going to do is to show you what that looks like. The acids and bases look like in a red cabbage solution. We have six test tubes here that have a little water in them, and I'm going to add the purple cabbage juice to each one as our indicator. Two, three, four, five, six. Next, we'll add a household chemical to each one. In the first one, we'll add some Drano. In the second one, we'll add some baking soda. These are both bases. We'll add some vinegar, orange juice, and finally we'll add some concentrated hydrochloric acid. So here you can see some common household chemicals. A very strong base is green. A very strong acid is red. So red cabbage is a really good acid base indicator.