Draw Lewis structures that satisfy the octet rule for the following molecules and ions: c. SO₃²⁻

Verified step by step guidance

1. Determine the total number of valence electrons in the molecule. Sulfur (S) has 6 valence electrons, each oxygen (O) has 6 valence electrons, and the 2− charge adds 2 more electrons.
2. Calculate the total number of valence electrons: 1 S (6 electrons) + 3 O (3 x 6 electrons) + 2 extra electrons from the charge = 26 valence electrons.
3. Place the least electronegative atom, sulfur, in the center, and arrange the three oxygen atoms around it.
4. Connect each oxygen atom to the sulfur atom with a single bond, using 2 electrons per bond, which accounts for 6 electrons.
5. Distribute the remaining 20 electrons to satisfy the octet rule for each oxygen atom first, and then place any remaining electrons on the sulfur atom.

Key Concepts

Lewis Structures

Lewis structures are diagrams that represent the bonding between atoms in a molecule and the lone pairs of electrons that may exist. They use dots to represent valence electrons and lines to represent bonds between atoms. Understanding how to draw Lewis structures is essential for visualizing molecular geometry and predicting reactivity.

Octet Rule

The octet rule is a chemical rule of thumb that states atoms tend to bond in such a way that they each have eight electrons in their valence shell, achieving a stable electron configuration similar to that of noble gases. This rule helps predict the arrangement of electrons in molecules and is particularly useful in understanding the stability of ions and compounds.

Formal Charge

Formal charge is a concept used to determine the distribution of electrons in a molecule or ion. It is calculated by taking the number of valence electrons of an atom, subtracting the number of non-bonding electrons, and half the number of bonding electrons. Minimizing formal charges in Lewis structures helps identify the most stable arrangement of atoms and electrons.