Acetic acid is a weak acid that dissociates into acetate ion and hydronium ions in solutions:

CH₃COOH_(aq) + H₂O_(l) ⇌ H₃O⁺_(aq) + CH₃COO^-_(aq)

The value of the dissociation constant (K_a) for acetic acid is 1.78×10^-5. If you require a buffer of pH 5.25, what would be the ratio of [CH₃COO^-]/[CH₃COOH] that you would use?