Formal Charge and Lewis Structures

The video tutorial explains the Lewis structure of the IO4- ion, detailing the distribution of 32 valence electrons among iodine and oxygen atoms. It discusses the initial structure where iodine is central, surrounded by oxygen atoms, and the octet rule is fulfilled. The tutorial then calculates formal charges, revealing a need for optimization. By forming double bonds, the formal charges are adjusted to be closer to zero, resulting in a more stable structure. The final structure is enclosed in brackets with a negative sign, indicating the ion's charge.

What is the total number of valence electrons in the IO4- ion?

• 30

• 36

• 32

• 34

Which atom is placed at the center of the IO4- Lewis structure?

• Hydrogen

• Carbon

• Oxygen

• Iodine

How many valence electrons does each oxygen atom have after fulfilling the octet rule?

• 9

• 7

• 8

• 6

What is the formal charge on iodine before any adjustments are made?

• 0

• +1

• +2

• +3

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

• -1

• +1

• +2

• 0

Why is it important to adjust the formal charges in a Lewis structure?

• To increase the number of valence electrons

• To make the structure more stable

• To change the central atom

• To add more atoms

How many double bonds are formed with oxygen to adjust the formal charges?

• 1

• 4

• 3

• 2

What is the formal charge on iodine after forming double bonds?

• -1

• +2

• 0

• +1

What is the formal charge on the oxygen atoms with double bonds after adjustment?

• -1

• 0

• +1

• +2

Why are brackets used in the final Lewis structure of IO4-?

• To indicate it is a molecule

• To show it is an ion

• To highlight the central atom

• To separate different atoms