Formal Charges and Lewis Structures

The video tutorial explains how to draw the Lewis structure for ClO3-. It begins by calculating the total valence electrons and arranging the atoms with Chlorine in the center. The initial structure is formed by distributing electrons to satisfy the octet rule. The tutorial then addresses the formal charges, showing a +2 charge on Chlorine and -1 on each Oxygen. To optimize the structure, electrons are moved to form double bonds, resulting in a formal charge of zero on Chlorine and two Oxygens, with one Oxygen retaining a -1 charge. The final structure is enclosed in brackets to indicate its ionic nature.

How many total valence electrons are present in the ClO3- ion?

• 26

• 25

• 27

• 24

Which atom is placed at the center of the ClO3- Lewis structure?

• Oxygen

• Chlorine

• Hydrogen

• Nitrogen

How many valence electrons are used to form chemical bonds between the atoms initially?

• 8

• 10

• 6

• 4

What is the formal charge on the chlorine atom before any adjustments?

• +2

• 0

• -1

• +1

What is the formal charge on each oxygen atom before any adjustments?

• -1

• 0

• +1

• -2

What structural change is made to reduce the formal charge on chlorine?

• Removing electrons from oxygen

• Adding a hydrogen atom

• Adding more electrons to chlorine

• Forming double bonds with oxygen

After forming double bonds, what is the formal charge on the chlorine atom?

• -2

• +1

• 0

• -1

What is the formal charge on the oxygen atom that does not form a double bond?

• -2

• 0

• -1

• +1

Why are brackets used in the final representation of the ClO3- structure?

• To denote resonance

• To highlight the central atom

• To show it is an ion with a negative charge

• To indicate it is a molecule