2013/06/23

Method for Lewis dot structures: The nitrate ion #56

A simple procedure for writing Lewis Dot Structures was given in a previous article entitled “Lewis Structures and the Octet Rule”. 
Several worked examples relevant to this procedure were given in previous posts please see the Sitemap - Table of Contents (Lewis Electron Dot Structures).

Let us consider the case of the nitrate ion. The molecular formula is NO3-.
 
Step 1: Connect the atoms with single bonds

Fig. 1 : Connect the atoms of NO3- with single bonds
Fig. 1 : Connect the atoms of NO3- with single bonds

Step 2:  Calculate the # of electrons in π bonds (multiple bonds) using  formula (1):



Where n in this case is 4. Where V = (5 +6*3) – (-1) = 24 , V is the number of valence electrons of the nitrate ion.
Therefore, P = 6n + 2 – V = 6 * 4 + 2 – 24  = 2     So, there is 1 double bond.


Step 3 & 4: The  dot resonance structures of  NO3-  are as follows:


Fig. 2 : Plausible Lewis Resonance Dot Structures of NO3-   

Therefore, there are 3 possible Lewis resonance structures for NO3-




4 comments:

  1. what is the Lewis structure of NO?

    ReplyDelete
    Replies
    1. Please see the following post:
      http://chem-net.blogspot.com/2013/09/lewis-dot-structure-nitrogen-monoxide.html

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  2. Which of the above structures contributes more to the resonance?

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    Replies
    1. The above resonance structures are all equivalent because of the same charge separation and bond order. They are all contribute equally to the resonance.

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