Chemistry - GOC Question with Solution | TestHub

Compare the conjugate bases : formate (no electron-donating group), acetate (methyl donates by +I and hyperconjugation, destabilising it), benzoate (the ring donates toward COOH by resonance, destabilising it a little less than a methyl does), and bicarbonate (the extra OH donates strongly by resonance). pKa values : HCOOH 3.75 $<$ PhCOOH 4.20 $<$ CH₃COOH 4.76 $<$ H₂CO₃ 6.35. Hence I $>$ III $>$ II $>$ IV.