Formal Charges in Sulfate Ion

Dr. B explains how to draw the Lewis structure for the sulfate ion (SO4 2-). The process begins with identifying the valence electrons for sulfur and oxygen, placing sulfur in the center, and arranging the oxygens around it. Initial bonds are drawn, and formal charges are calculated. To optimize the structure, electrons are moved to form double bonds, reducing formal charges. The final structure is enclosed in brackets to indicate the ion's charge, resulting in a stable Lewis structure for SO4 2-.

How many total valence electrons are present in the sulfate ion (SO4 2-)?

• 24

• 28

• 32

• 36

In the initial Lewis structure of SO4 2-, how many valence electrons are used to form bonds between sulfur and oxygen?

• 4

• 8

• 16

• 12

What is the formal charge on sulfur in the initial Lewis structure of SO4 2-?

• -1

• +1

• +2

• 0

What is the formal charge on each oxygen atom in the initial Lewis structure of SO4 2-?

• -1

• +1

• -2

• 0

Why is it necessary to adjust the initial Lewis structure of SO4 2-?

• To change the central atom

• To reduce the number of bonds

• To achieve a more stable structure with formal charges closer to zero

• To increase the total number of electrons

How are the formal charges on sulfur and oxygen adjusted in the improved Lewis structure of SO4 2-?

• By adding more electrons to sulfur

• By forming double bonds between sulfur and two oxygen atoms

• By changing the central atom

• By removing electrons from oxygen

What is the formal charge on sulfur in the final Lewis structure of SO4 2-?

• +2

• 0

• -1

• +1

What is the formal charge on the oxygen atoms involved in double bonds in the final Lewis structure of SO4 2-?

• 0

• -2

• -1

• +1

What is the formal charge on the oxygen atoms not involved in double bonds in the final Lewis structure of SO4 2-?

• +1

• -2

• -1

• 0

What is the final step in representing the Lewis structure of the sulfate ion?

• Placing brackets around the structure with the charge

• Changing the central atom

• Removing double bonds

• Adding more electrons