Question

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

Explanation:

Step1: Recall formal - charge formula

The formal - charge formula is $FC = V - N - \frac{B}{2}$, where $V$ is the number of valence electrons of the neutral atom, $N$ is the number of non - bonding electrons, and $B$ is the number of bonding electrons.

Step2: Analyze Structure 1

• For left N: Nitrogen has 5 valence electrons ($V = 5$). It has 2 non - bonding electrons ($N = 2$) and 6 bonding electrons ($B = 6$). So, $FC=5 - 2-\frac{6}{2}=0$.
• For center N: Nitrogen has 5 valence electrons ($V = 5$). It has 0 non - bonding electrons ($N = 0$) and 8 bonding electrons ($B = 8$). So, $FC = 5-0 - \frac{8}{2}=1$.
• For S: Sulfur has 6 valence electrons ($V = 6$). It has 4 non - bonding electrons ($N = 4$) and 4 bonding electrons ($B = 4$). So, $FC=6 - 4-\frac{4}{2}=0$.

Step3: Analyze Structure 2

• For left N: Nitrogen has 5 valence electrons ($V = 5$). It has 2 non - bonding electrons ($N = 2$) and 6 bonding electrons ($B = 6$). So, $FC = 5-2-\frac{6}{2}=0$.
• For center N: Nitrogen has 5 valence electrons ($V = 5$). It has 0 non - bonding electrons ($N = 0$) and 8 bonding electrons ($B = 8$). So, $FC=5 - 0-\frac{8}{2}=1$.
• For S: Sulfur has 6 valence electrons ($V = 6$). It has 2 non - bonding electrons ($N = 2$) and 6 bonding electrons ($B = 6$). So, $FC=6 - 2-\frac{6}{2}=1$.

Step4: Analyze Structure 3

• For left N: Nitrogen has 5 valence electrons ($V = 5$). It has 6 non - bonding electrons ($N = 6$) and 2 bonding electrons ($B = 2$). So, $FC=5 - 6-\frac{2}{2}=-1$.
• For center N: Nitrogen has 5 valence electrons ($V = 5$). It has 0 non - bonding electrons ($N = 0$) and 8 bonding electrons ($B = 8$). So, $FC=5 - 0-\frac{8}{2}=1$.
• For S: Sulfur has 6 valence electrons ($V = 6$). It has 2 non - bonding electrons ($N = 2$) and 6 bonding electrons ($B = 6$). 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 S = 0
Structure 2:
Formal charge for N (left) = 0
Formal charge for N (center) = 1
Formal charge for S = 1
Structure 3:
Formal charge for N (left) = - 1
Formal charge for N (center) = 1
Formal charge for S = 1