1. www.soran.edu.iq Inorganic chemistry Assistance Lecturer Amjad Ahmed Jumaa  Reaction of Bases.  Conjugated Acid-Base pairs. 1

2. www.soran.edu.iq 1.9: Reaction of Bases: 1- Reaction of bases with salts of transition metals: Base + soluble transition metal salt → in soluble transition metal hydroxide. + Salt. 3Ca(OH) 2 (s) + 2CrCl 3 (aq) → 2Cr(OH) 3 (s) + 3CaCl 2 (aq). 2- Reaction of amphoteric hydroxides with acid and bases: Al(OH) 3 (s) + NaOH(aq) → NaAl(OH) 4 (aq). Acid base 1.9: Reaction of Bases: 1- Reaction of bases with salts of transition metals: Base + soluble transition metal salt → in soluble transition metal hydroxide. + Salt. 3Ca(OH) 2 (s) + 2CrCl 3 (aq) → 2Cr(OH) 3 (s) + 3CaCl 2 (aq). 2- Reaction of amphoteric hydroxides with acid and bases: Al(OH) 3 (s) + NaOH(aq) → NaAl(OH) 4 (aq). Acid base Al(OH) 3 (s) + 3HCl(aq) → AlCl 3 (aq) + 3H 2 O. Base acid. Al(OH) 3 (s) + 3HCl(aq) → AlCl 3 (aq) + 3H 2 O. Base acid.

3. www.soran.edu.iq Reaction of strong base with amophoteric metals: 3Al(s) + 2NaOH(s) + 6H 2 O → 2NaAl(OH) 4 (aq) + 3H 2 (g). Reaction of strong base with amophoteric metals: 3Al(s) + 2NaOH(s) + 6H 2 O → 2NaAl(OH) 4 (aq) + 3H 2 (g).  Conjugated Acid-Base pairs: In an acid-base reaction the acid(HA), gives up its proton(H + ) and produce a new base(A - ). The new base(A - ), is related to the original acid, and is called a conjugated base. The original base(B - ), after accepting a proton(H + ) gives a new acid (HB), which is called a conjugate acid.  Conjugated Acid-Base pairs: In an acid-base reaction the acid(HA), gives up its proton(H + ) and produce a new base(A - ). The new base(A - ), is related to the original acid, and is called a conjugated base. The original base(B - ), after accepting a proton(H + ) gives a new acid (HB), which is called a conjugate acid.

4. www.soran.edu.iq It may be noted that in any acid-base reaction, there are two conjugate acid-base pairs The two conjugate pairs are: HA and A - ; and HB and B -.

5. www.soran.edu.iq  Examples of conjugate acid-base pairs: Let us consider the reaction between HCl (aq), and NH 3 (aq):  Examples of conjugate acid-base pairs: Let us consider the reaction between HCl (aq), and NH 3 (aq): In this case HCl(acid), and Cl - (conjugate base) NH 3 (base), and NH 4 + (conjugate acid), comprise the two acid- base conjugate pairs. The reaction between acetic acid and water to form the conjugate base CH 3 COO - and the conjugate acid H 3 O +. In this case HCl(acid), and Cl - (conjugate base) NH 3 (base), and NH 4 + (conjugate acid), comprise the two acid- base conjugate pairs. The reaction between acetic acid and water to form the conjugate base CH 3 COO - and the conjugate acid H 3 O +.

6. www.soran.edu.iq  Thus we can conclude: (A) A weak base has strong conjugate acid. (B) A weak acid has a strong conjugate base.  Thus we can conclude: (A) A weak base has strong conjugate acid. (B) A weak acid has a strong conjugate base.