We could go on expanding the S octet, but this would start to move the formal charges away from zero; thus we stop here. Draw a Lewis dot structure for sulfuric acid, H2SO4. What is the formal charge on the sulfur atom? 9 years ago. Lv 6. Assume that all of the S-O bonds are single bonds. Favorite Answer. Relevance. sluggermatt15. And so if there's any way to get this formal charge as close to 0 as possible, that would be the preferred dot structure. H 2 SO 4 Step 8 Picture so Far: (numbers next to atoms are their formal charges) The bottom resonance structure is the best because all the formal charges are zero. Okay, I’m still in school, so I know this. If you can draw multiple valid Lewis dot structures for a particular molecule or ion dot Sulfuric Acid is H2SO4 2. Formal Charge = Number of valence electrons (of the atom in isolation) - Number of free electrons (non-bonding) - Number of links (or electrons shared) Both H: FC = 1 - 0 - 1 bond = 0. So this dot structure might look like we're done, but we have a lot of formal charges. Lewis's H2SO4 structure has a total of 32 valent See Lewis Lewis's big list Transcript: This is the H2SO4 Lewis structure: sulphuric acid. Some practice of assigning formal charge is necessary before you master this technique. This suggests that the Lewis structure is not very good. We think so because all the atoms in (f) have a formal charge of zero. Knowing this information, it is much easier to draw Lewis's structure for H2SO4. Draw a Lewis dot structure for sulfuric acid, H2SO4. Formal charge = valence electrons - non bonding valence - bonding valence/2. FC = 6 - 2 - (4/2) = 2. Formal charges are just that - a formality, a method of electron book-keeping that is tied into the Lewis system for drawing the structures of organic compounds and ions. Later, we will see how the concept of formal charge can help us to visualize how organic molecules react. Add up the valence electrons in each element. 1. The formal charge is a hypothetical charge assigned from the dot structure. What is the molecular geometry of the molecule Now, if we look at Lewis structures (e) and (f) with formal charges, we can predict with reason that structure (e) should be stable. Draw the Lewis dot structure and calculate the formal charges of the oxygen and sulphur atoms of H2SO4. Assume that all of the S-O bonds are single bonds. Answer Save. The formal charges in a structure tell us the “quality” of the dot structure. Therefore, 2(# valence for H) + (# of valence for S) + 4(# valence for O). For Lewis's structure for H2SO4 you have to take official charges into account to find the best Lewis structure for the molecule. Notice that the sum of the absolute values of the formal charges is 4, although this species is uncharged. We will see how to make it better in step 8. Step 8 in determining the Lewis Structure of H2SO4. We have -1, plus 2, and -1. Upper O: FC = 6 - 4 (there should be two pairs of free electrons on this atom) - … H 2 SO 4 Step 7 ... 6 - (1/2)2 = -1, O with H --> 6 - 4 - (1/2)4 = 0. What is the formal charge on the sulfur atom? Step 7 in determining the Lewis Structure of H2SO4. H has 1, S has 6, and O also has 6. Determine and illustrate formal charges for Lewis structures When you draw Lewis structures, sometimes the electrons are shared in a way which seems "unfair." And usually molecules like to have-- like to minimize the formal charge. For instance, in (CH 3 ) 3 NO, to give N 8 electrons (and not more, since N can't have more than 8), you have to draw a … 2 Answers.