Use formal charge to choose the best Lewis structure for CH3SOCH3 .
Solution 13SAQ We want to demonstrate that the best structure for CH SOC3 is as3ollows: Thus the answer b) Step 1 of 3 We have to consider some rules that regulate if we have a good Lewis structure or not: 1. The sum of all formal charge in a neutral molecule must be zero. 2. The sum of all formal charges in a ion must equal the charge of the ion. 3. Small (or zero) formal charges on individual atoms are better than large ones. 4. When formal charge cannot be avoided, negative formal charge should residue on the most electro-negative atom 5- Every atom has to be surrounded by a number of valence electrons corresponding to the group of the periodic table to which they belong, 6- Every atom has to respect the octet rule. Step 2 of 3 We have to remember the general formula to calculate the formal charge of an atom is Formal charge = number of valence electrons – (number of non-bonding electrons) + ½ number of bonding electrons)