How To Draw Bond-Line Structures From Condensed Structures

Zigzag lines are used for carbon chains in bond-line structures. The end of the line and two lines coming together represent a carbon. Hydrogens are not shown. However, you have to know that every carbon wants to have four bonds. So, you can determine the number of hydrogens. For example, carbon 1 has one bond and that means it must be attached to three hydrogens. Carbon 2 has two bonds and must be attached to two hydrogens

Double bonds are represented as two lines.

Triple bonds are a bit tricky. When you draw a triple bond, you have to draw it straight. The carbons on the triple bond and those attached to the triple bond must be straight but the rest of the carbons will be on a zigzag. Many students do not realize that the place where a triple bond starts represents a carbon (C2) and a place where it ends is also a carbon (C3). Keep that in mind when drawing triple bonds.

Rings are also drawn using bond-line structures.

First, you need to convert the condensed structure into the Lewis structure to see what is bonded to what. Then, you can number the carbons in the chain and draw out the zigzag numbering carbons again. Carbon 2 is attached to a CH₃ and carbon 3 is attached to an OH.

First, you will number the carbons and draw out the Lewis structure. Then number the carbons in the Lewis structure and draw out the zigzag. Don’t forget to include the double bond between carbon 1 and 2 and attach two CH₃ groups to carbon 4.

First, you will number the carbons and draw out the Lewis structure. Notice there is a carboxylic acid functional group. Next draw out the zigzag and add double bond O and OH to the last carbon.

Where there is a hill, draw your group UP, not down. When there is a valley, draw your group DOWN, not up.