2.2.14 - Formal Charge

Question 1

What does formal charge do?

Answer 1

predicts which Lewis structure is more favourable when more than one is possible (often with expanded octets)

Question 2

What is formal charge?

Answer 2

the hypothetical charge that can be used to determine the correct Lewis structure and which one is most stable

Question 3

What is the formula for Formal charge?

Answer 3

Formal Charge = # valence electrons - (0.5 bonding electrons + # electrons in lone pairs)

Question 4

How many times does formal charge have to be calculated?

Answer 4

once for each atom

Question 5

What must be assumed for the formula for Formal charge to work?

Answer 5

equal sharing with bonding electrons and lone pairs are owned by one atom

Question 6

What is the formula for the change in formal charge?

Answer 6

FCmax - FCmin

Question 7

What will favourable lewis structures have?

Answer 7

change in FC closest to zero, the neg charges on the most electronegative atoms