Chemical Nomenclature Lesson

Organic Chemistry Introduction

Module 7 - Year 12 ​

​What we will cover:

• What is organic chemistry?

• Syllabus inquiry questions

• IUPAC nomenclature

• Alkanes

• Alkenes

• Alkynes

• Isomerism

Open Ended

What is your understanding of organic chemistry?

​What is organic chemistry?

• Life is carbon based ​

  • ​all Earthly life

  • pharmaceuticals, petrochemicals, agrichemicals, lubricants, solvents, plastics, fuels, explosives

• Synthesising compounds or creating new ones

​What we will learn in this module:

​IUPAC Nomenclature

Naming is essential and specific

• allows us to name incredibly complex chemical structures and every chemist around the world knows what we are talking about ​

longest-word.pdf (cw39.com)

• generally it is based on the:

  • functional groups off this chain

  • number of carbons in the chain

  • the position of the functional groups

  • alphabetical order

• different ways to represent:

  • ​molecular

  • structural

  • condensed structural

  • skeletal structural

​Types of structures

​Structural

​IUPAC name or preferred name?

​

• ​2-hydroxypropane - 1, 2, 3-tricarboxylic acid

• Citric acid

​Prefixes

We count the longest carbon chain, and this forms the basis of the organic compounds name ​

​

You need to remember these! ​

​Hydrocarbons

Alkanes, alkenes alkynes

​

​

​

Multiple Choice

Choose the alkane

​Alkanes

• contain only C and H atoms (hydrocarbon)

• contain single bonds ​

• saturated molecule - cannot bond with anything else

• has the general formula: ​C_nH_2n+2

• Naming alkanes:

  • identify the longest continuous carbon chain

  • ​identify any alkyl side chains

  • number the carbon atoms in the chain (to give lowest numbers to side chains)

    ​

​Example:

1. ​Count the number of carbons in the longest chain

2. Use the prefix and attach to

   -ane ​

​Alkyl side chains:

• Branches off of the main carbon chain

• suffix is -yl

• Helps us to number the larger structure

• Must have the lowest number possible attached

• alphabetical order

​

3-ethyl-2-methylhexane​

​

​Your turn:

​Your turn:

Multiple Choice

What is the suffix for single bonded hydrocarbons?

• -yne
• -ene
• -ane
• -one

Multiple Choice

Name this alkane

• Methane
• Ethane
• Propane
• Butane

Multiple Choice

How many C-C single bonds in this compound?

• 2
• 5
• 15
• 20

Multiple Choice

Which is the structures with IUPAC nomenclature

2,2,4-trimethylpentane

​Alkenes

• have a double bond between at least two carbons

• unsaturated

• general formula: C_nH_2n

• Naming:

  • same as alkanes

  • replace -ane with -ene

  • place number before -ene to indicate where the double bond is

​Your turn:

​Your turn:

​Alkynes

• contains at least one triple bond​ between 2 carbons

• ​uses the suffix -yne

• unsaturated

• ​general formula: C_nH_2n-2

• ​naming:

  • same as alkanes

  • replace -ane with -yne

  • place number before -yne to indicate where the triple bond is​

​prop-1-yne

​Your turn:

​Your turn

Draw: 2,2-dimethyloct-3-yne​

​Your turn

Draw: 2,2-dimethyloct-3-yne​

​Isomers

• molecules that have the same number and type of atoms, but have a different structure

• can have very different physical and chemical properties

• 3 types of isomers:

  • Chain = have differing numbers of alkyl groups

  • Position = change in position of bonds or functional groups

  • Functional group = same atoms, but different functional groups (we will learn more about this later)

​Chain Isomers

​Position Isomers

​Functional Isomers

​What we will cover next:

• Functional groups

  • haloalkanes, ​alcohols, amines, aldehydes, ketones, carboxylic acids, amides, esters