Question

question A) What is Formal Charge? Calculate the formal charge on all elements of O3 & CO32−. B) Use Lewis symbols to show electron transfer between the following atoms to form Cations and anions: (a) K and S (b) Ca and O (c) Al and N (d)Al and O

Answer 1

Formal charge is the charge allocated to atoms present in molecule. The electrons in all bonds present between the atoms sharing electrons equally between them.

FC = Velence electron – lone electron – bond pair

Formal charge on O3

O a=O b-O c

Fc (a)= 6 – 4 – 2 = 0

Fc (b)= 6 – 2 – 3 = 1

Fc (c)= 6 – 6 – 1 = -1  

Formal charge on CO3^2-

Fc (a)= 6 – 4 – 2 = 0

Fc (b)= 6 – 6 – 1 = -1

Fc (c)= 6 – 6 – 1 = -1  

Lewis symbols  shown in diagram

Answer 2

Remember that formal charge is calculated by taking the # of valence electrons, minus the lone electrons and the bonds, and we show that charge next to the molecule. Take ::O=C=O:: for example. Each O's formal charge would be calculated by: 6 (valence) - 4 (lone electrons) - 2 (bonds) = 0.