Formal Charges and Valence Electrons in Sulfite Ion

The video tutorial explains how to calculate the formal charge for each element in the sulfite ion (SO3 2-). It begins with an introduction to the concept of formal charge and its importance in determining the most likely Lewis structure. The tutorial then provides a step-by-step calculation of the formal charge for sulfur, considering its valence electrons and the concept of an expanded octet. Following this, the formal charge for oxygen is calculated, differentiating between single and double-bonded oxygen atoms. The video concludes by validating the calculated charges against the overall ionic charge, confirming the most favorable Lewis structure for the sulfite ion.

What is the purpose of calculating formal charges in a molecule?

• To identify the type of chemical reaction

• To calculate the bond angles

• To find the most stable Lewis structure

• To determine the molecular weight

How many valence electrons does sulfur have in the sulfite ion?

• 10

• 8

• 6

• 4

What is the formal charge of sulfur in the sulfite ion?

• +1

• -1

• -2

• 0

How many unbonded electrons are present on a single-bonded oxygen atom in the sulfite ion?

• 4

• 2

• 6

• 8

What is the formal charge of a single-bonded oxygen atom in the sulfite ion?

• -1

• 0

• -2

• +1

How many unbonded electrons are present on the double-bonded oxygen atom in the sulfite ion?

• 6

• 4

• 2

• 8

What is the formal charge of the double-bonded oxygen atom in the sulfite ion?

• +1

• -2

• -1

• 0

Why is sulfur able to have more than eight valence electrons in the sulfite ion?

• It is in group 14

• It is an exception and can have an expanded octet

• It forms ionic bonds

• It is a metal

What is the total ionic charge of the sulfite ion?

• -1

• +2

• 0

• -2

Which statement best describes the most favorable Lewis structure for the sulfite ion?

• All atoms have a formal charge of zero

• The total formal charges add up to the ion's charge

• The sulfur atom has a formal charge of -1

• All oxygen atoms have a formal charge of +1