Question

Formal charge for C2H4. Formal charge for C2H2. Formal charge for HNO3. Show work

Answer 1

Formal charge (FC)
FC = VE - NBE - ½BE ..... VE = valence electrons, NBE = nonbonding electrons, BE = bonding electrons

FC of each carbon = 4 - 0 - 8/2 = 0
FC of each H = 1 - 0 - 2/2 = 0


The oxidation state of hydrogen is +1. The sum of the oxidation states of a neutral compound is zero. Therefore, the oxidation state of each carbon is -2. Carbon can have oxidation states from -4 to +4.


C2H4 ==> 2(-2) + 4(+1) = 0


Formal charge is useful for checking the validity of a Lewis structure, while oxidation numbers are useful for naming salts and for balancing charge in redox reactions.

C2H2 -> 2.4 + 2.1 = 10 valance electrons

for the formal charges on the carbon = VE - BE - NBE = 4 - 4 - 0 = 0

formal charge for Hydrogen VE - BE - NBE = 1 - 1 - 0 = 0

formal chage is 0

we have 24 valance electrons for HNO3 from the above lewis structure

Reference

for HNO3

https://www.youtube.com/watch?v=DcHgX8uHg2k

for C2H2

https://www.youtube.com/watch?v=yGVMl8r-MN8