Chemistry : Definition List 2

  1. Acid dissociation – (expressed quantitatively) acid dissociation constant, Ka, is nothing more than the equilibrium constant for the dissociation reaction of an acid in water.
    Relative strength of an acid ↑ (increases), its Ka ↑ (increases) and its pKa ↓(decreases).
    (The Ka and pKa of an acid depend on the strength of an acid, but not its concentration.)
  2. Base hydrolysis – base hydrolysis constant, Kb, nothing more than the equilibrium constant for the hydrolysis reaction of a base in water.
    Relative strength of a base ↑ (increases), its Kb ↑ (increases) and its pKb ↓ (decreases).
    (The Kb and pKb of an acid depend on the strength of an acid, but not its concentration.)
  3. Overall Relationship : Acid strength ↑ , Ka ↑ , pKa ↓ , conjugate base strength ↓, Kb ↓, pKb ↑
  4. Strength of a reagent (Ka / pKa and Kb / pKb) – the completeness of a reaction in water. (dissociation = ionisation or electrolytic nature)
    The stronger the acid, the more electrolytic it is, because it conducts electricity better due to the greater number of ions in solution.
    The stronger the base, the more readily it undergoes hydrolysis when mixed with water

AcidNamepKa
Cl3CCOOHTrichloroacetic acid0.64
Cl2HCCOOHDichloroacetic acid1.27
H2SO3Sulfurous acid1.82
HClO2Chloroacetic acid1.90
ClH2CCOOHChloroacetic acid2.82
HFHydrofluoric acid3.15
HNO2Nitrous acid3.41
HCOOHFormic acid3.74
H3CCOOHAcetic acid4.74
2,4-(H3C)2C6H3NH3+2,4-dimethylanilinium5.08
4-H2NC6H4NH3+4-aminoanilinium6.18
H3CO3Carbonic acid6.36
4-O2NC6H4OH4-nitrophenol7.15
HClOHypochlorous acid7.46
HBrOHypobromous acid8.72
NH4+Ammonium9.26
HCNHydrogen cyanide9.36
HIOHypoiodous acid10.66

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