PF4- Ion Structure and Properties

The video tutorial explains how to draw the Lewis structure for the PF4- ion. It begins by calculating the total number of valence electrons, considering phosphorus and fluorine atoms, and the negative charge. The phosphorus atom is placed at the center, surrounded by fluorine atoms, and initial bonds are formed. The tutorial addresses the octet rule, showing how to complete the octets for fluorine atoms. It then discusses the placement of extra electrons on phosphorus, which can exceed the octet rule, and calculates formal charges to ensure the structure is correct. Finally, it emphasizes the importance of using brackets to denote the negative charge of the ion.

How many valence electrons does phosphorus contribute to the PF4- Lewis structure?

• 7

• 3

• 5

• 9

What is the total number of valence electrons in the PF4- ion?

• 32

• 34

• 36

• 30

Which atom is placed at the center of the PF4- Lewis structure?

• Nitrogen

• Oxygen

• Phosphorus

• Fluorine

How many fluorine atoms are bonded to the central phosphorus atom in PF4-?

• 3

• 5

• 2

• 4

What is the issue after completing the octets for fluorine atoms in PF4-?

• Incorrect charge

• Incorrect atom placement

• Not enough electrons used

• Too many electrons used

How many extra valence electrons are there after completing the octets for fluorine?

• 1

• 2

• 3

• 4

Why can phosphorus hold more than eight valence electrons in PF4-?

• It is highly electronegative

• It is an exception to the octet rule

• It has a smaller atomic radius

• It forms ionic bonds

Where are the extra valence electrons placed in the PF4- structure?

• On a fluorine atom

• On the central phosphorus atom

• They are removed

• In a new bond

What charge does the central phosphorus atom have in the PF4- ion?

• Neutral

• Double negative

• Negative

• Positive

Why are brackets used around the PF4- Lewis structure?

• To denote formal charge

• To show it is an ion

• To highlight the central atom

• To indicate it is a molecule