Building an Inorganic Molecule - II

Task: Build Ozone, O₃

Time: 7 minutes

Ozone has an unusual bonding structure.  Before using CAChe to build the structure of ozone, draw the Lewis structure and determine the Formal Charge on each of the oxygen atoms. You will need this information in order to complete your structure correctly.

1. To open a new Workspace select File|New from the menu bar.
2. Select the Atom icon . Your cursor turns into the atom tool .
3. Select the arrow button in the element type box and select oxygen.  Since the hybridization is not the same on every oxygen atom, we'll change that after we draw the skeleton.
4. Click in the workspace to draw an oxygen atom. Click and drag two more times to create the ozone skeleton.
5. Use the Lewis structure you drew as a guide to adjust the bond order.  Click on the select tool and click on one of the O-O bonds. Select the arrow button in the bond type box and select   to make it double.  The other O-O bond should already be .
6. Next, we'll adjust the hybridization on two of the oxygen atoms.  Click on the select tool   to select one of the oxygen atoms in the double bond. Holding down the shift key, select the other oxygen atom. Select the arrow button in the hybridization type box and select sp² -trigonal plane .
7. Finally, we'll adjust the charges.  When you computed the Formal Charges, you found that each oxygen atom has a different charge.  Click on the select tool , select one of the oxygen atoms, then click the up or down arrow button in the charge box to select appropriate charge for that atom. Repeat this step for each of the other oxygen atoms.
8. Click on the select tool and click in the workspace (not on any atoms or bonds) to select the entire molecule.
9. To fix the geometry of the ozone molecule, select Beautify|Geometry from the menu bar. 
10. To save your finished molecule select File|Save and save it as "ozone".