3.33 b

[Isabelle De Rego 1A]

For question 3.33b they want the lewis structure for COCl2, when I originally drew this. I had carbon as the central atom, with oxygen and chlorine surrounding it, each with a single bond and 6 electrons around each of the three atoms. In the answers, the bond between carbon and oxygen is a double bond. I assume that this double bond makes the formal charge closer to zero, but how am I supposed to know where to put these double bonds and when it is appropriate?

[princessturner1G]

With the double bond between carbon and oxygen, this satisfies the octet rule. Now all the atoms have eight electrons.

[Yadira Flores 1G]

If you calculate the formal charge for the lewis structures of the two you have you will also be able to see that the correct Lewis structure equals zero, meaning its the most stable, therefore the correct one. Hope that helps.