Lewis structure of H 2 SO 3 (Sulfurous acid): Generating Lewis structures Any chemical element. Capitalize the first letter in chemical symbol and use lower case for the remaining letters: Ca, Fe, Mg, Mn, S, O, H, C, N, Na, K, Cl, Al. Functional groups: D, T, Ph, Me, Et, Bu, AcAc, For, Tos, Bz, TMS, tBu, Bzl, Bn, Dmg parenthesis () or brackets []. Common compound names. What is a Lewis structure? How to create a Lewis dot structure? Step 1: Count the total number of valence electrons For CO₂: Carbon has 4 valence electrons, each Oxygen has 6 valence electrons. Total valence electrons = 4 + (2 × 6) = 16 electrons Step 2: Determine the central atom The central atom is usually the least electronegative atom (excluding hydrogen). Carbon is less electronegative than oxygen, so carbon is the central atom.

Step 3: Draw single bonds between central atom and surrounding atoms Connect carbon to each oxygen with a single bond. Each single bond uses 2 electrons. Electrons used so far: 2 bonds × 2 electrons = 4 electrons Remaining electrons: 16 - 4 = 12 electrons Step 4: Add lone pairs to outer atoms Complete the octet for each oxygen atom by adding lone pairs. Each oxygen needs 8 electrons total. Each oxygen already has 2 electrons from bonding, so each needs 6 more electrons (3 lone pairs). Electrons used: 4 (bonds) + 12 (lone pairs) = 16 electrons Step 5: Check if central atom has complete octet Carbon currently has only 4 electrons (2 bonds). It needs 8 electrons to complete its octet. Since we've used all 16 valence electrons, we need to form double bonds. Step 6: Verify the Lewis structure Check that: • All atoms have complete octets (or duet for hydrogen) • The total number of electrons used equals the total valence electrons • The most stable structure is achieved (lowest formal charges) Lesson on generating Lewis dot structure WebQC is a web application with a mission to provide best-in-class chemistry tools and information to chemists and students. By using this website, you signify your acceptance of Terms and Conditions and Privacy Policy . © 2026 webqc.org All rights reserved · Contact us