Do Lewis structures give correct geometries for carbonate and nitrate?
The Lewis structures have three groups of e- around the central atoms, so trigonal planar e- pair geometry is predicted. 5.38 What are the bonding and structure of the carbon dioxide molecule? (a) There are 2(6) + 4 = 16 valence e- in the molecule: (b) From the Lewis structure, we see that there are 2 e- groups at the central C atom. These will be linearly arranged. Each of the 2 e- groups involves a double bond, so each involves a sigma bond and a pi bond. So, there are 2 sigma bonds linearly arranged at the central C. (c) Make the model with your kit! You will see that the model is linear. 5.39 Bond order in carbon dioxide (a) The bond order for the carbon-oxygen bond is 2. The bond order is just the sum of the sigma and pi bonds, and the Lewis structure shows a double bond between C and O. (b) C-O is 140 pm and C=O is 120 pm. In carbon dioxide, there are C=O bonds, so the observed bond length of 115 pm makes sense. Its close to the 120 pm of an ordinary C=0 bond. The smaller than or
