1. IC3.30.3 Homologous series © Oxford University Press 2011 Homologous series

2. IC3.30.3 Homologous series © Oxford University Press 2011 Everyone smells slightly different because of the mix of compounds in their sweat. Dogs are better than humans at detecting these differences in sweat.

3. IC3.30.3 Homologous series © Oxford University Press 2011 The compounds that give sweat its smell are carboxylic acids. The carboxylic acids make up a homologous series. The series includes:  methanoic acid  ethanoic acid  propanoic acid.

4. IC3.30.3 Homologous series © Oxford University Press 2011 All carboxylic acid molecules have the functional group –COOH, in which the atoms are arranged like this:

5. IC3.30.3 Homologous series © Oxford University Press 2011 As you go up any homologous series, there is a gradual change in some properties, such as boiling point and density.

6. IC3.30.3 Homologous series © Oxford University Press 2011 1.Describe the trends in density and boiling point from methanoic acid to propanoic acid. Density decreases and boiling points increase down the homologous series.

7. IC3.30.3 Homologous series © Oxford University Press 2011 2. What is the name of the homologous series that has this functional group? the carboxylic acids