Potassium has a formal charge of +1. Oxygen has a formal charge of -1. Both charges cancel each other and give an overall charge of 0.
Work Step by Step
Formal Charge (FC) = [number of valence electrons] - [number of non-bonding electrons] - 1/2 [shared electrons] FC (potassium) = 1-0-0= +1 FC (oxygen) = 6-6-1 = -1 FC (carbon) = 4-0-4 = 0 FC (hydrogen) = 1-0-1 = 0