Hydroxide Ion Properties and Charges

The video tutorial explains how to calculate the formal charge for each atom in the hydroxide ion (OH-). It begins by introducing the concept of formal charge and the equation used for calculation. The tutorial then demonstrates the calculation for oxygen, showing that it has a formal charge of -1, and for hydrogen, which has a formal charge of 0. The video concludes by summarizing the formal charges and explaining why these charges are expected given the overall charge of the hydroxide ion.

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

• Add the number of bonded and unbonded electrons.

• Subtract the number of unbonded electrons.

• Determine the number of valence electrons.

• Identify the number of bonded electrons.

How many valence electrons does oxygen have in the hydroxide ion?

• 7

• 6

• 5

• 4

What is the formal charge of oxygen in the hydroxide ion?

• +1

• 0

• -1

• -2

How many unbonded electrons does hydrogen have in the hydroxide ion?

• 1

• 3

• 0

• 2

What is the formal charge of hydrogen in the hydroxide ion?

• 0

• +1

• -2

• -1

Why is it expected to see a negative charge on one of the atoms in the hydroxide ion?

• Because the ion is positively charged.

• Because the ion is neutral.

• Because the ion has an overall positive charge.

• Because the ion has an overall negative charge.

Which atom in the hydroxide ion carries the negative charge?

• Oxygen

• Hydrogen

• Neither hydrogen nor oxygen

• Both hydrogen and oxygen

What is the overall charge of the hydroxide ion?

• +1

• 0

• -1

• -2