Pop Quiz

Pop Quiz There are five structural isomers for hexane, C6H14. Draw the five structures using simplified structural formulae.

Pop Quiz - Solution  The molecular formula of C6H14 contains the maximum number of H atoms for 6C (CnH2n+2) so it can cannot contain double bonds or rings. Therefore the only functional group that can be present is an alkane.  When you draw them it is a good idea to have a system whereby you start with the longest chain, then move to shorter chains with an increasing number of substituents, moving them to different positions on the chain as you go. Watch that you don't repeat structures.

Chapter 2: Polymers Learning Objective: Understand the structure and naming of polymers Use correct terminology related to polymer chemistry Understand the difference between natural and synthetic polymers

2.1 Introduction to Polymers Where does silk come from? -silkworm -silk is very strong, thin -silk is used for clothes, embroidery, etc. -silk is an example of a group of compounds called polymers

The General Structure of Polymers Before we get started, write down the following definitions: Polymer – a large, usually chain-like molecule that is built from small molecules Monomer – one of the repeating small molecules that make up polymers Homopolymer – a polymer of a single type of monomer Copolymer – a polymer made of two or more different types of monomers combined

The General Structure of Polymers Task – Paper Clips

The General Structure of Polymers Ethene to polyethene Ethene monomers  polyethene polymer

Task Draw the polymer from propene monomers. Is it a homopolymer or a copolymer?

Task - Solution

Natural and Synthetic Polymers Natural polymers are made of living things, from bacteria to mammals. Examples of naturally occurring polymers are silk, wool, DNA, cellulose and proteins Synthetic polymers are usually made from monomers sourced from plants or from petrochemicals. Examples of synthetic polymers include nylon, polyethylene, polyester and Teflon. Uses of polyesters – clothes, fabrics, etc. Teflon- used as a non-stick coating for pans and other cookware

2.2 – Synthetic Addition Polymers Addition polymer: a very long organic molecule formed as the result of addition reactions between monomers with unsaturated carbon-carbon bonds Plastic: a synthetic substance that can be moulded (often under heat and pressure) and that then retains its given shape

What does the ‘n’ mean? The number of units.

Task Go on page 85, copy from down the first 5 examples from the table. You need to know the uses of polymers for the test!

Task Do questions: 1, 2, 3, 4, 6, 9 on page 83.