Acetic acid has Ka = 1.8 x 10^-5. What is Kb for the acetate ion at 25 degrees Celsius?

1. Acetic acid and acetate form a conjugate pair, so their constants multiply to Kw. 2. Rearranged, the base constant equals Kw divided by the acid constant. 3. Divide the coefficients: 1.0 divided by 1.8 is 0.56. 4. Subtract the exponents: minus 14 minus minus 5 gives minus 9. 5. Combine: 0.56 x 10^-9, written as 5.6 x 10^-10. 6. Multiplying the two constants instead would give a value near 10^-19. _Source: OpenStax Chemistry (CC BY 4.0), Ch 14 "Acid-Base Equilibria", section 14.4 Hydrolysis of Salt Solutions_