Chem - Polymer Revolution 12.2

Polymer Revolution

Charlotte Jones

12.2 - Alkenes

What are alkenes?

Ethenes have double bonds, so they are unsaturated hydrocarbons. Non-cyclic alkenes have the general formular of CnH2n They are named by:

• The number of carbons eg. Propene has 3 carbons
• Where the double bond is attached eg. But-1-ene means the double bond is on the first carbon.

Skeletal Formula is used  commonly to show the structure of alkenes. Eg. But-1-ene.

The boiling points of alkenes increase as the number of carbons increase.

There are cycloalkenes and dienes (with 2 double bonds).

Shapes of alkenes

The C=C bonds in all alkenes are arranged in the same way. C=C bonds are in a planar arrangement, as the electrons around the carbons repel eachother to an angle…