Question

a student proposes the following lewis structure for the phosgene (cocl₂) molecule. :o: || :cl — c — cl: assign a formal charge to each atom in the students lewis structure. atom formal charge c o right cl left cl

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 of the neutral atom, $N$ is the number of non - bonding electrons, and $B$ is the number of bonding electrons.

Step2: Calculate formal charge of carbon (C)

Carbon has 4 valence electrons ($V = 4$). In the Lewis structure, it has 0 non - bonding electrons ($N = 0$) and 8 bonding electrons ($B = 8$). Using the formula $FC = V - N-\frac{B}{2}$, we get $FC=4 - 0-\frac{8}{2}=4 - 0 - 4=0$.

Step3: Calculate formal charge of oxygen (O)

Oxygen has 6 valence electrons ($V = 6$). It has 4 non - bonding electrons ($N = 4$) and 4 bonding electrons ($B = 4$). Using the formula $FC = V - N-\frac{B}{2}$, we get $FC = 6-4-\frac{4}{2}=6 - 4 - 2=0$.

Step4: Calculate formal charge of chlorine (Cl)

Chlorine has 7 valence electrons ($V = 7$). Each chlorine atom has 6 non - bonding electrons ($N = 6$) and 2 bonding electrons ($B = 2$). Using the formula $FC = V - N-\frac{B}{2}$, we get $FC=7 - 6-\frac{2}{2}=7 - 6 - 1=0$. For both left and right Cl, the formal charge calculation is the same.

Answer:

atom	formal charge
O	0
right Cl	0
left Cl	0