Acid & conjugate Bases and pKa

Hydroiodic Acid (HI)

pKa: -10
Conjugate base: iodide (i^-)

Sulfuric Acid (H₂SO₄)

pKa: -9
Conjugate base: Hydrogen Sulfate (HSO₄)

Hydrochloric Acid (HCl)

pKa: -7
Conjugate base: Chloride (Cl^-)

Protonated ether

pKa: -3.8
Conjugate base: ether

protonated ketone

pKa:-2.9
Conjugate base: ketone

protonated alcohol

pKa: -2.5
Conjugate base: alcohol

Hydronium (H₃O⁺)

pKa: -1.7
Conjugate base: water

Nitric acid (HNO₃)

pKa: -1.4
Conjugate base: nitrate (NO₃^-)

Phosphoric acid (H₃PO₄)

pKa: 2
Conjugate base: phosphate (H₂PO₄^-)

amino acid

pKa: 2

Protonated aniline

pKa: 4.6
Conjugate base: aniline

Carboxylic acid

pKa: 4.8
Conjugate base: carboxylate

Protonated pyridine

pKa: 5.2
Conjugate base: pyridine

Carbonic acid

pKa: 6.4
Conjugate base: bicarbonate

Ammonium

pKa: 9.2
Conjugate base: ammonia (NH₃)

Phenol

pKa: 10
Conjugate base: phenoxide

bicarbonate

pKa: 10.2
Conjugate base: carbonate

1° ammonium

pKa: 10.6
Conjugate base: 1° amine

2° ammonium

pKa: 11
Conjugate base: 2° amine

cyclopentadiene

pKa: 16
Conjugate base: cyclopentadienyl anion

amide

pKa: 15.0

water

pKa: 15.7
Conjugate base: hydroxide

1° alcohol

pKa: 16
Conjugate base: alkoxide

3° alcohol

pKa: 18
Conjugate base: tert-butoxide

ketones

pKa: 19
Conjugate base: enolate

esters

pKa: 23
Conjugate base: ester enolate

alkynes

pKa: 25
Conjugate base: acetylide

hydrogen gas

pKa: 35
Conjugate base: hydride

ammonia

pKa: 38
Conjugate base: amide base

alkenes

pKa: 44

alkanes

pKa: 50
Conjugate base: organometallic