The correct name of the compound is potassium bromate.
KBrO₃ contains a metal, so it is an ionic compound.
The name of an ionic compound is: name of metal cation + name of anion
.
Name the metal
The name of the cation is the name of the metal — potassium
The ion has only one charge (+1), so the name of the ion does not use a Roman numeral in parentheses.
Name the anion
BrO₃⁻ is an oxyanion. Name = (stem)ate = bromate.
Name the compound
The names of salts do not use multiplying prefixes like mono- or di-.
∴ metal ion + anion → potassium bromate
