Simple method for writing Lewis Structures: Chlorine Dioxide ClO2
A simple procedure for writing Lewis electron dot 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 the Lewis dot structures of chlorine dioxide ClO2. Chlorine dioxide is used mainly for bleaching of wood pulp, for bleaching of flour and for the disinfection of municipal drinking water
How can we draw the Lewis structure of ClO2?
Step 1: Connect the atoms with single bonds. Chlorine is the central atom.
![Connect the atoms with single bonds Connect the atoms with single bonds](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjI2A3dCGa8IbK-1bUGI_B8Jk_-_O4DYbBmqXEKXDl4SB8ZoRgosZ1SRWLCZU-LVaNkE14uOSf-u4noxhMV_7QVkpdwe01o4_3o0dXU7upX9CRVk0gUZjD5_WJ2a1Zir1mtjW928eLy_h0/s1600/clo2.png)
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 ClO2 consists of three atoms.
Where V = (6 + 6 + 7 ) = 19
Therefore, P = 6n + 2 – V = 6 * 3 + 2 – 19 = 1 So there is only 1 π electron in ClO2
So the structure of Step 1 is the Lewis structure.
Electrons are placed around each atom so that the octet rule is obeyed. Since the number of valence electrons is odd the octet rule will not be obeyed in all atoms. Formal charges are assigned and equalized using resonance.
Step 3 & 4: The Lewis structures of ClO2 are derived below:
![Figure 1: Plausible Lewis structures for chlorine dioxide. Oxygen is more electronegative than chlorine so it can accommodate better the negative charge. Structure 3 has no formal charge. The real molecule is a hybrid of the above Lewis structures Figure 1: Plausible Lewis structures for chlorine dioxide. Oxygen is more electronegative than chlorine so it can accommodate better the negative charge. Structure 3 has no formal charge. The real molecule is a hybrid of the above Lewis structures](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjRCiXipN7bAdlJGg8vOVQTV4SmIt5eJtO4zjHnK-ahJOdueJDZU61HbhP3LwXJ0l-WYrbJiNQJYg3kclRIdSwhRJc0HN2xorhyphenhyphenXCUrCMEAfSOnusjB1ZJqnudP3ucZKAN_eTtEoNE7aVI/s1600/ClO2_final.png)