Answer
The intermediate is:
Work Step by Step
1. Analyze the arrows.
First arrow (Left):
- Tail: It is breaking the pi bond...
- Head: to give the electron pair to the oxygen.
Second arrow (Right):
- Tail: It is taking 2 electrons from the oxygen...
- Head: to form a bond between the oxygen and that carbon.
2. Now, let's find the formal charges:
The oxygen had neutral charge, then it lost a pi bond (+1), and gained 2 electrons (-2) = -1 formal charge.
The other oxygen had (-1) as a charge, then it lost 2 electrons (+2), and formed a bond (-1) = Neutral formal charge.
