Lewis Structures and Valence Electrons

The video tutorial explains how to draw the Lewis structure for bromine pentachloride (BrCl5). It begins by counting the valence electrons for bromine and chlorine, then proceeds to draw the bonds between the atoms. The concept of an expanded octet for bromine is introduced, allowing it to hold more than eight electrons. The tutorial continues by completing the octets for chlorine atoms and placing the remaining electrons on bromine. Finally, the formal charges are checked to confirm the most stable Lewis structure.

How many valence electrons does bromine contribute in BrCl5?

• 5

• 7

• 10

• 12

What is the total number of valence electrons in BrCl5?

• 35

• 42

• 48

• 50

How many valence electrons are used in forming bonds between bromine and chlorine in the initial setup?

• 14

• 12

• 8

• 10

Why is it acceptable for bromine to have more than eight valence electrons in BrCl5?

• Bromine is in period 3 and can expand its octet.

• Bromine is in period 6 and can expand its octet.

• Bromine is in period 4 and can expand its octet.

• Bromine is in period 5 and can expand its octet.

How many valence electrons are left after completing the octets of all chlorine atoms?

• 2

• 4

• 6

• 0

Where are the remaining valence electrons placed in the final Lewis structure of BrCl5?

• They are not used

• On the central bromine atom

• On an external atom

• On one of the chlorine atoms

What is the formal charge on each atom in the finalized Lewis structure of BrCl5?

• +1

• -1

• 0

• +2

Why is the formal charge important in determining the best Lewis structure?

• It indicates the polarity of the molecule.

• It helps in identifying the most stable structure.

• It determines the number of bonds.

• It shows the molecular geometry.

What is the significance of having a formal charge of zero on all atoms in BrCl5?

• It shows the molecule is ionic.

• It means the molecule is reactive.

• It suggests the most stable Lewis structure.

• It indicates a non-polar molecule.

What is the molecular geometry of BrCl5 based on its Lewis structure?

• Tetrahedral

• Trigonal bipyramidal

• Square pyramidal

• Octahedral