What is the formal charge on the indicated carbon atom?
A) -2
B) -1
C) 0
D) +1
E) +2

Question

What is the formal charge on the indicated carbon atom? 
A) -2 
B) -1 
C) 0 
D) +1 
E) +2

Quizplus · Accepted Answer

To calculate the formal charge on a given atom, we use the formula: 
Formal charge = Valence electrons - Nonbonding electrons – Half of the bonding electrons 
The carbon atom in question has 4 valence electrons and is bonded to 3 other atoms, which contributes 3 bonding electrons (each bond contributes 2 electrons, but the bond is shared between two atoms so only half of it is counted for each atom). 
There are no nonbonding electrons on this carbon atom. 
Formal charge = 4 - 0 - 3/2 = -1 
Therefore, the formal charge on the indicated carbon atom is -1, which corresponds to answer choice B.

What Is the Formal Charge on the Indicated Carbon Atom