Page 12 - Pharmaceutical analytical chemistry |

The equilibrium constant for this reaction is called ionization constant or
dissociation constant.
Weak acids as acetic acid

CH3COOH H+ + CH3COO-

[H+] [CH3COO-]
Ka= ________________

[CH3COOH]

Weak bases as ammonium hydroxide

NH4OH NH4+ + OH-

[NH4+] [OH-]
Kb = ________________

[NH4OH]

4. Neutralization reactions

• A neutralization reaction is a reaction of an acid and a base that
results in an ionic compound (salt) and possibly water. The salt
formed consists of cations obtained from the base and anions
obtained from the acid.

• We write molecular, complete ionic and net ionic equations
* 2 HCl (aq) + Ca(OH)2 (aq) ⎯→ CaCl2 (aq) + 2H2O (l)
s.a. s.b.

 2 H+(aq) + 2Cl-(aq) + Ca2+(aq) + 2OH-(aq) → Ca2+(aq) + 2Cl-(aq) + 2H2O (l)

H+ (aq) + OH- (aq) ⎯→ H2O (l)

* HCN (aq) + KOH (aq) ⎯→ KCN (aq) + H2O (l)

HCN (aq) + OH- (aq) ⎯→ CN- (aq) + H2O (l)
w.a.

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