Chemistry - GOC Question with Solution | TestHub

A base deprotonates water (pKa 15.7) only if its own conjugate acid is weaker than water, i.e. has a higher pKa. (a) ethoxide : EtOH pKa 16 - yes. (b) acetylide : terminal alkyne pKa 25 - yes. (c) Cl⁻ : HCl pKa -7 - no, far too weak. (d) NH₂⁻ : NH₃ pKa 38 - yes. (e) ketone enolate : α C-H pKa ≈ 20 - yes. (f) acetate : AcOH pKa 4.8 - no. So the bases are a, b, d and e.