Question

How can I identify alkenes?

Answer 1

Alkenes are hydrocarbons that possess a double bond and have the general formula `C_nH_2n`, where n refers to the number of carbon.

For example if we look at the simplest alkene - ethene, for example - the formula is `C_2H_4`, which follows the general formula above, and has the following structure:

Notice again that the number of carbons is 2, so our n value would be 2. This results in a 2n value of 4, which corresponds to the number of hydrogens here.

It is possible for compounds to have multiple double bonds, and the general formula for these will be represented as `C_nH_2n-_2y` where y is the number of additional double bonds in the compound.