Aim: How can we name and draw hydrocarbons?

Do Now: 1.Take out a calculator and reference tables.

2.Write the chemical formula and draw an example of one molecule of the following:

Methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane. 3. What makes this a homologous series?

Answer to Do Now• Methane• Ethane• Propane• Butane• Pentane• Hexane• Heptane• Octane• Nonane• Decane

Alkenes• Contain at least one double bond.• We can use tables P and Q to name and draw

alkenes as well. The general formula for alkenes is:• Example: What is the molecular formula for

ethene?

• Draw a molecule of ethene.

How can we tell where the double bond is when there are more than two carbon atoms?

• Example: Draw a molecule of butene.

• How many ways can butene be drawn? • Molecules that have the same molecular compositions

but different structural formulas are called isomers. • We can determine where the double bond is by

numbering the carbon atoms. The carbons are numbered so that the double bond is at the lowest number. Example: 2-hexene

More ExamplesWrite the formula for each of the following alkenes.

Draw a molecule of each of the following. • propene

• 3-Pentene

• 5-Heptene

Alkynes• Contain at least one triple bond.• Also use tables P and Q to name and draw. The

molecular formula for alkynes is:• Example: What is the chemical formula for ethyne?

• Draw a molecule of ethyne.

More ExamplesWrite the formula for the following alkynes. Draw an

example of a molecule for each of the following alkynes.

• 3-pentyne

• 5-octyne

Activity/Homework • Review Book pages 197-198. Copy and answer

questions 1-4, 8-12, 15-18.