You have been studying how to name various types of alkanes when provided with diagrams. However, you also need to know how to diagram the molecule when provided with only its name or molecular formula.

Drawing an unbranched alkane ("straight chain") is quite straightforward. The name of the parent chain indicates the number of carbons in the molelcule . Simply draw a straight chain containing the correct number of carbon atoms. Next, add sufficient hydrogen atoms to provide each carbon with four single bonds.

Drawing branched alkanes can be more difficult.

To draw a branched alkane, follow these steps:

1. Study the name of the molecule. How many carbons are contained in the parent chain? Draw a straight chain containing this number of carbons.
   
   
2.  Number the carbons from left to right.
   
   
3. Draw in the alkyl branches, attaching them to their numbered locations on the parent chain (as stipulated in the molecule's name).
   
   
4. Add hydrogen atoms to give each carbon four single bonds.
   
   
5. When drawing a cycloalkane, connect the parent chain into a continuous loop. See communication example 3 on page 372 of your text.

Check Your Understanding

Go to your textbook and complete "Practice" questions 7 (a-g) and 10  on pages 370-371 and Section 9.2 question 5 on page 373. Check your answers by clicking the banner beneath.