What is the molecular geometry of the sulfate ion (SO4^2-)?

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Q: What is the molecular geometry of the sulfate ion (SO4^2-)?

Solution: The sulfate ion has four bonding pairs and no lone pairs, resulting in a tetrahedral molecular geometry.

Steps: 7

Step 1: Identify the sulfate ion, which is represented as SO4^2-. This means it has one sulfur (S) atom and four oxygen (O) atoms.
Step 2: Determine the total number of valence electrons. Sulfur has 6 valence electrons, and each oxygen has 6 valence electrons. Since there are four oxygens, that adds up to 24 electrons from oxygen. The sulfate ion has a -2 charge, which means we add 2 more electrons. So, total valence electrons = 6 (S) + 24 (4 O) + 2 (charge) = 32 electrons.
Step 3: Draw the Lewis structure for the sulfate ion. Place the sulfur atom in the center and connect it to the four oxygen atoms with single bonds. Each bond uses 2 electrons, so 4 bonds use 8 electrons, leaving us with 24 electrons.
Step 4: Distribute the remaining 24 electrons to the oxygen atoms to satisfy their octet rule. Each oxygen will get 6 electrons (3 lone pairs) to complete their octet.
Step 5: Check the formal charges. To minimize formal charges, convert two lone pairs from two of the oxygen atoms into double bonds with sulfur. This gives sulfur a formal charge of 0 and each oxygen a formal charge of 0.
Step 6: Count the bonding pairs and lone pairs around the sulfur atom. There are 4 bonding pairs (the bonds to the oxygen atoms) and 0 lone pairs.
Step 7: Determine the molecular geometry based on the number of bonding pairs and lone pairs. With 4 bonding pairs and no lone pairs, the molecular geometry is tetrahedral.