Question

for each resonance form, determine the formal charge for each atom. structure 1: :n≡n—ö: formal charge for n (left)= formal charge for n (center)= formal charge for o= structure 2: :n═n═ö: formal charge for n (left)= formal charge for n (center)= formal charge for o= structure 3: :n—n≡o: formal charge for n (left)= formal charge for n (center)= formal charge for o=

Explanation:

Step1: Recall formal - charge formula

The formula for formal charge is $FC = V - N - \frac{B}{2}$, where $V$ is the number of valence electrons, $N$ is the number of non - bonding electrons, and $B$ is the number of bonding electrons. For nitrogen, $V = 5$; for oxygen, $V = 6$.

Step2: Calculate formal charges for Structure 1

Left - hand N

$V = 5$, $N = 2$, $B = 6$. So, $FC=5 - 2-\frac{6}{2}=0$.

Center N

$V = 5$, $N = 0$, $B = 8$. So, $FC = 5-0 - \frac{8}{2}=1$.

O

$V = 6$, $N = 6$, $B = 2$. So, $FC=6 - 6-\frac{2}{2}=- 1$.

Step3: Calculate formal charges for Structure 2

Left - hand N

$V = 5$, $N = 2$, $B = 4$. So, $FC=5 - 2-\frac{4}{2}=1$.

Center N

$V = 5$, $N = 0$, $B = 8$. So, $FC = 5-0 - \frac{8}{2}=1$.

O

$V = 6$, $N = 4$, $B = 4$. So, $FC=6 - 4-\frac{4}{2}=0$.

Step4: Calculate formal charges for Structure 3

Left - hand N

$V = 5$, $N = 4$, $B = 2$. So, $FC=5 - 4-\frac{2}{2}=0$.

Center N

$V = 5$, $N = 0$, $B = 8$. So, $FC = 5-0 - \frac{8}{2}=1$.

O

$V = 6$, $N = 2$, $B = 6$. So, $FC=6 - 2-\frac{6}{2}=1$.

Answer:

Structure 1:
Formal charge for N (left) = 0
Formal charge for N (center) = 1
Formal charge for O = - 1
Structure 2:
Formal charge for N (left) = 1
Formal charge for N (center) = 1
Formal charge for O = 0
Structure 3:
Formal charge for N (left) = 0
Formal charge for N (center) = 1
Formal charge for O = 1