When you tutor high school chemistry, you cover a little organic chemistry. Today we visit a topic that rarely gets asked about during tutoring, but is very useful to know at the college level.

 
In my previous post on organic chemistry, I introduced the topic and showed a few drawings. They were of this style:

Recall that carbon, which appears as C in the diagrams, makes four bonds. (Each bond is a line to another atom.) Notice that most of the bonds are between carbon and hydrogen (H).

Since bonds usually are between C and H, chemists often don’t draw the H atoms. They’re understood to be there unless a bond clearly goes to something else. In such cases, only the bonds between carbons or between carbons and other atoms are shown, like so:

With the hydrogens left out, the diagram becomes simpler to understand. For example, you can more easily tell the how many carbons it has.

Some people take simplification a step further, writing only sticks for the carbon skeleton. Each corner represents a carbon atom. Therefore, all three of the following diagrams show butane:

The simplified drawing styles really come in handy for showing molecules with features such as alcohol. Here’s an example:

How we know the molecule is 2-pentanol will be covered in a future post:)

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.