Using Lewis Structures to Determine Molecular Bonding

USING LEWIS STRUCTURES TO DETERMINE MOLECULAR BONDING 

In order to fully appreciate and understand molecular structure, you will need to be able to construct representations of various molecules. One of the easiest ways to do this is using Lewis structures. The procedure is a bit more complicated than for ionic compounds because of the increasing complexity of covalent compounds. The basic procedure for constructing Lewis diagrams of molecules consists of 4 steps  

Q Write a skeleton structure of the molecule. For this step, you will need to write the symbols for each atom in the molecule and connect each using a pair of dots or a dash. This is one of the more difficult steps since you are not told directly which atom is attached to which. In general, the chemical formula is written in the same order that the elements are connected in the molecule. When multiple atoms are connected to the same atom, the central atom is usually written first (e.g., in the CC14 molecule, the carbon is the central atom and the four chlorine atoms are bonded around it). Very often, the central atom is the least electronegative element. 

Q Put the rest of the electrons on the central atom. The remaining number of electrons is the total number (from step 1) minus the number you placed on the surrounding atoms in step 3. If you don t have enough electrons, you will need to determine if double or triple bonds are present. If you have too many electrons on the central atom, don t worry about it. You will see later in the chapter why this is possible. 

Sample Draw a Lewis structure for the molecule CF4, carbon tetrafluoride. 

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Using Lewis structures to determine molecular bonding... 

Using Lewis Structures to Determine Molecular Bonding... 

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