Chapter 8 Bonding and Molecular Structure - 8-5 Exceptions to the Octet Rule - Case Study - Questions - Page 306: 2

See the answer below.

There are 30 valence electrons: $\begin{smallmatrix} H&-&\ddot{O}&-&\ddot{O}&-&C&-&\ddot{O}:&\leftrightarrow& H&-&\ddot{O}&-&\ddot{O}&-&C&=&\ddot{O}\\ &&\ddot{}&&\ddot{}&&&&\ddot{}&&&&\ddot{}&&\ddot{}&&&&\ddot{}\\ &&&&&&||&&&&&&&&&&|&&\\ &&&&&&:O:&&&&&&&&&&:O:&&\\ &&&&&&&&&&&&&&&&\ddot{}&& \end{smallmatrix}$ All atoms have a formal charge of zero except for the oxygen atom that only makes a single bond to the carbon, whose formal charge is -1.