Imagine that a new polyatomic anion called "platoate" is invented. What would an acid of "platoate" be named?
Platoic Acid
While naming Carboxylic Acids we know that when the Carboxylic Acid looses proton it is converted into corresponding conjugate base called as Carboxylate.
Examples:
HCOOH → HCOO⁻ + H⁺
Formic acid Formate Ion
H₃CCOOH → H₃CCOO⁻ + H⁺
Acetic acid Acetate Ion
H₅C₂COOH → H₅C₂COO⁻ + H⁺
Propanoic acid Propanoate Ion
Therefore, if the conjugate base is Platoate then the corresponding acid will be Platoic Acid means we will replace the -ate by -ic acid i.e.
RCOO⁻ + H⁺ → RCOOH
Platoate Ion Platoic Acid