Give the formal charge on the sulfur atom in a Lewis structure for the sulfate ion in which every atom satisfies the octet rule.
Based off my lewis structure, I think the formal charge of the the sulfur atom would be +2. Is that correct?
yes
To determine the formal charge on the sulfur atom in the sulfate ion, we first need to draw the Lewis structure for the molecule correctly.
The sulfate ion (SO4^2-) consists of one sulfur atom bonded to four oxygen atoms. Each oxygen atom has two lone pairs of electrons. The sulfur atom should have six electrons in its valence shell (due to its position in group 16 of the periodic table) and needs to form bonds with four oxygen atoms.
To distribute the electrons, we place one oxygen atom on each side of the sulfur atom, connecting them with single bonds. This uses up a total of eight valence electrons (4 from the sulfur atom and 4 from the oxygen atoms). We then place the remaining two oxygen atoms, each containing two lone pairs of electrons, on opposite sides of the sulfur atom.
Now, we need to count the electrons around the sulfur atom to determine its formal charge. The formal charge formula is:
Formal charge = valence electrons - (lone pair electrons + 0.5 * bonding electrons)
For the sulfur atom in the sulfate ion, the valence electrons are 6. The oxygen atoms each have 6 valence electrons, contributing 2 lone pairs (4 electrons) and one bond (2 electrons) to the sulfur atom. Therefore, the formal charge on the sulfur atom is:
Formal charge = 6 - (4 + 0.5 * 8) = 6 - (4 + 4) = 6 - 8 = -2
Hence, the formal charge on the sulfur atom in the sulfate ion is -2, not +2 as you originally suggested.
To determine the formal charge on the sulfur atom in the sulfate ion (SO4^2-), we need to follow a step-by-step process:
Step 1: Determine the total number of valence electrons.
Sulfur (S) is in Group 16 of the periodic table and has 6 valence electrons. Oxygen (O) is in Group 16 as well and has 6 valence electrons each. Since there are four oxygen atoms, the total number of valence electrons is:
6 (sulfur) + 4 × 6 (oxygen) + 2 (charge of the sulfate ion) = 32 electrons.
Step 2: Draw the Lewis structure.
To satisfy the octet rule for all atoms, start by placing one oxygen atom in the center and connect it to sulfur (S) through a single bond. The remaining three oxygen atoms will be bonded to the sulfur atom using double bonds (two shared pairs of electrons each). Make sure to arrange the remaining lone pairs of electrons on the oxygen atoms. The final structure should look like this:
O
||
O-S-O
||
O
Step 3: Assign formal charges.
The formal charge of an atom can be calculated by using the formula:
Formal Charge = Valence electrons - (Number of lone pair electrons + Number of bonds)
For sulfur (S), let's calculate its formal charge:
Valence electrons in sulfur = 6
Number of lone pair electrons = 0 (since sulfur does not have any lone pairs)
Number of bonds = 4 (since sulfur is bonded to four oxygen atoms)
Formal charge of sulfur (S) = 6 - (0 + 4) = +2
Therefore, your initial assumption is correct. The formal charge on the sulfur atom in the sulfate ion is +2.