Formal Charge and Lewis Structures

The video tutorial explains how to write the Lewis structure for bromic acid (HBrO3). It begins by identifying the total number of valence electrons and placing the least electronegative element, bromine, at the center. Hydrogen is placed on the outside, typically bonded to oxygen. The tutorial demonstrates how to distribute electrons to form chemical bonds and fulfill the octet rule. It then calculates formal charges to identify the most stable structure. Adjustments are made by forming double bonds, allowing bromine to have an expanded octet, which results in a more favorable Lewis structure with minimized formal charges.

What is the total number of valence electrons in HBrO3?

• 26

• 30

• 24

• 28

Which element is placed at the center of the HBrO3 Lewis structure?

• Bromine

• Hydrogen

• Oxygen

• None of the above

How many valence electrons are used after forming initial bonds in HBrO3?

• 14

• 12

• 10

• 8

What is the formal charge on the central bromine atom before any adjustments?

• +1

• 0

• +2

• -1

Why is it necessary to form double bonds in the HBrO3 structure?

• To increase the number of valence electrons

• To reduce the formal charges

• To decrease the number of atoms

• To make the structure more complex

What happens to the formal charge on bromine after forming one double bond?

• It becomes +1

• It becomes 0

• It becomes -1

• It remains +2

How many valence electrons does bromine have in the final structure?

• 8

• 12

• 14

• 10

What is the formal charge on the oxygen atoms in the final structure?

• +1

• 0

• -2

• -1

What is the significance of achieving zero formal charges in the Lewis structure?

• It increases the number of bonds

• It makes the structure more colorful

• It indicates a more stable structure

• It decreases the number of electrons

Which element can have an expanded octet in the HBrO3 structure?

• Oxygen

• Hydrogen

• Bromine

• None of the above