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Name: Kimberly B.
Status: educator
Age: 20s
Location: N/A
Country: N/A
Date: Saturday, July 06, 2002

In writing the formulas for carbon bonds, is there a certain method for attaching the hydrogens?

I am unsuccessful at finding help in this area. Thank you.


Yes. Carbon can have only 4 bonds connected to it. The first step is to attach all of the carbons. Lets take C3H8 (propane) as an example. First connect all the carbons in a straight chain.
   C - C - C

Next, put all the hydrogens on. This is accomplished by adding enough H's to each carbon such that 4 atoms (carbons or hydrogens) are connected.
      H   H  H
      |   |  |
  H - C - C - C - H
      |   |  |
      H   H  H

Voila, there is propane.

       H   H
       |   |
   H - C = C - H

And so on.

A good source on the Internet for more detailed information on alkane connectivity can be found by doing a search on your favorite search engine for "alkane(s)" or "alkane connectivity"

Darin Wagner

The element carbon, C, has an unusual property of forming chemical bonds with itself. This is not unique to carbon, but carbon does this more readily than any other element. Carbon has 4 outer (valence) electrons that can form these bonds. It may use one of these electrons to bond to another carbon atom, leaving three to bond with other elements (for example, H3C-CH3, which is ethane). Carbon can bond with itself using two of the four outer electrons leaving two electrons to bond with other elements (for example, H2C=CH2, which is ethylene). Carbon can bond with itself using three of the four outer electrons (for example, HC=-CH which is acetylene. I can't type three horizontal lines with the fonts available.) It may use all four of the electrons to bond to itself, leaving none to bond with other elements (diamond is an example).

You can find this topic discussed in detail in any introductory text in "Organic Chemistry". You can also find this discussed on web sites. Try searching for terms like: "elementary organic chemistry", "introductory organic chemistry", "carbon to carbon bonds".

Vince Calder

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