 Remember, when you're carrying out these three different tests on these three different functional groups of organics, what you're simply trying to do is say, if I was to place in front of you a bottle and that bottle contained a colourless liquid, and I said that colourless liquid could have a carbon-carbon double bond, it could have a hydroxyl group, or it could have a carboxylic acid group, how are you going to determine which of those it has, then hopefully what you will have now is a series of tests that you can carry out. Hopefully, if you carry out the first one, you'll get a positive result, which will tell you positively what the identity is, such as if you added some carbonate ions through the addition of something like say sodium carbonate, and you had effervescence, you could say, okay, well we've got an organic acid. If we didn't, okay, then we've got a double bond, carbon-carbon double bond, or we've got a hydroxyl group, so maybe we'll add bromine water next, and that way we'll know we'll eliminate the carbon-carbon double bond, and that will leave us with the hydroxyl group, so if there's no reaction with the bromine water, then we can look at going to our oxidation step, and then that too should tell us not only whether or not there is a hydroxyl group present, but also whether that hydroxyl group is present on an end carbon, on a middle carbon, or on a carbon that's attached to three other carbons. So that's what this is about. We're going to go into some more precise techniques around spectroscopy to identify some of these functional groups in a little bit more specific detail, but this gives you a nice little introduction, and hopefully a review of some of the reactions that you've already looked at when trying to identify different functional groups of organic compounds. Thanks for watching.