Question

In the cyanide anion CN-, what is the formal charge on the nitrogen atom?

Answer 1

1) The sum of the oxidation states of all the atoms in an ion is equal to the charge on the ion.
2) The more electronegative elements always have the negative oxidation number
Carbon has four valence electrons and Nitrogen has three.
CN-
In order for a N to complete an octet it must bond to three atoms but we only have the C atom. the only way for the N to form a comple noble gas structure is to form a triple bond with the C atom.
N has an oxidation number of -3
Based on the Charge of ion on the compound CN-, C must be +2