Pages

▼

Simple Procedure for writing Lewis Structures – Lewis Structures for nitrogen dioxide (NO2)

Simple Procedure for writing Lewis Structures – Lewis Structures for nitrogen dioxide (NO2)
Home > Lewis structures and the Octet rule > Simple Procedure for writing Lewis Structures - Lewis Structures for NO2+ and HCN > Lewis dot of Nitrogen Monoxide (NO) > Simple Procedure for writing Lewis Structures – Lewis Structures for nitrogen dioxide (NO2)

Simple Procedure for writing Lewis Structures – Lewis Structures for nitrogen dioxide (NO2)


A simple procedure for writing Lewis structures is 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).

Another example for writing Lewis structures following the above procedure is given below:


Let us consider the case of  nitrogen dioxide NO2.  NO2 is a red-brown gas with a pungent and irritating odour. Let us draw the Lewis dot structures of NO2 molecule (resonance structures of nitrogen dioxide):




It is one of the most prevalent oxides of nitrogen, NO is the other one. Both are toxic gases with NO2 being a highly reactive oxidant and corrosive. NO2 forms quickly from emissions from cars, power plants and off-road equipment. NO2   can also come from appliances inside homes that burn fuels such as gas, kerosene and wood. In general, the NOx gases  are believed to worsen asthmatic conditions and bronchitis, react with the oxygen in the air to produce ground-level ozone, which is also an irritant and eventually form nitric acid when dissolved in water. When dissolved in atmospheric moisture the result is acid rain which can damage trees and crops, entire forest ecosystems, lakes.



Step 1: The central atom will be the N atom since it is the less electronegative. Connect the atoms with single bonds:


Step 2: Calculate the # of electrons in π bonds (multiple bonds) using formula (1) in the article entitled “Lewis Structures and the Octet Rule”.

Where n in this case is 3 since NO2 consists of three atoms.

Where V = (5 + 6 + 6 ) = 17  

Therefore, P = 6n + 2 – V = 6 * 3 + 2 – 17 = 3   Thus, there are 2 π electrons in NO2  and a lone electron.

Therefore, there is a double bond and a lone electron that is not involved in multiple bonding  and 1 double bond must be added to the structure of Step 1 and a lone electron.



Step 3 & 4: One double bond must therefore be placed to the structure in Step1. Therefore, the Lewis dot structures of nitrogen dioxide NO2 are as follows:

Figure I.1: Lewis structures for NO2. Odd electron species cannot obey the octet rule on every atom (without dimerizing) but may be treated in the same fashion. The odd electron must be considered as a lone electron, not involved in multiple bonding. Placing the lone electron on O would give larger charge separation which is less favorable

 

As it can be seen above the Lewis dot structures of nitrogen dioxide do not obey the octet rule. The N atom has 7 electrons around it (violation of the octet rule).

Relevant Posts

Lewis Structures and the Octet Rule
Lewis dot of Nitrogen Monoxide (NO)
Lewis Electron - Dot Structure of the nitrite ion NO2-


 Key Terms

Lewis electron structure of nitrogen dioxide NO2 | Simple methof for, Lewis structures of  NO2 molecule, resonance structures of nitrogen dioxide, octet rule, Lewis dot structures of nitrogen dioxide NO2, violation of the octet rule, simple procedure for drawing Lewis structures


στις

No comments:

Post a Comment