Formal Charge and Valence Electrons

The video tutorial explains how to calculate the formal charges for the hydronium ion (H3O+). It begins by determining the formal charge of hydrogen, which is zero, as all its electrons are involved in bonding. The tutorial then calculates the formal charge of oxygen, which is +1, due to its lone pair and bonding electrons. This charge distribution aligns with the overall positive charge of the hydronium ion, indicating that the positive charge resides on the oxygen atom.

What is the first step in calculating the formal charge of an atom?

• Add the unbonded electrons

• Count the total number of electrons

• Identify the number of valence electrons

• Subtract the bonded electrons

How many valence electrons does hydrogen have?

• Four

• One

• Three

• Two

What is the formal charge of a hydrogen atom in H3O+?

• +1

• 0

• -1

• +2

In which group is oxygen found on the periodic table?

• Group 1

• Group 16

• Group 18

• Group 2

How many lone pair electrons does the oxygen atom in H3O+ have?

• Six

• Two

• Four

• None

What is the formal charge of the oxygen atom in H3O+?

• -1

• 0

• +1

• +2

What does the formal charge calculation reveal about the charge distribution in H3O+?

• The charge is evenly distributed

• The charge resides with the hydrogen atoms

• The charge resides with the oxygen atom

• There is no charge on the molecule

Why is it not surprising that the oxygen atom in H3O+ has a positive formal charge?

• Because the molecule is neutral

• Because hydrogen is negative

• Because oxygen is always positive

• Because the overall molecule has a positive charge