In this deck, we'll explore the characteristic reactions of three important families of organic compounds: alkenes, alcohols, and carboxylic acids. You'll learn how to distinguish between alkanes and alkenes, how ethanol is made and used, and how carboxylic acids behave as weak acids.

Let's start with alkenes. Unlike alkanes, which have only single carbon-carbon bonds, alkenes have at least one carbon-carbon double bond. This double bond is the key to their chemistry. It's an area of high electron density, making alkenes much more reactive than alkanes because the double bond can open up and allow other atoms to add on.

The main type of reaction that alkenes undergo is called an addition reaction. In an addition reaction, the carbon-carbon double bond breaks, and a new molecule is added across the two carbon atoms. This turns the unsaturated alkene into a saturated compound with only single bonds.

Because alkenes undergo addition reactions and alkanes don't, we can use this difference to test for them. The test uses bromine water, which is an orange-coloured solution. If you shake an alkene with bromine water, an addition reaction happens. The bromine adds across the double bond, and the orange colour of the bromine water disappears, becoming colourless. If you do the same with an alkane, nothing happens, and the solution stays orange.