Buffer Solution and Hydrolysis

A. Buffer solution (Buffer)Buffer solution is a solution that is able to maintain its pH although it added little to sour, slightly alkaline, or a little water (diluted).Buffer solution formulas as follows.a. Acid buffer solution are (a mixture of weak acid and alkali konjugasinya or salt of weak acid)
[H +] = Ka x [A]
                   n x [G]

Description:[A] = concentration of weak acid[G] = concentration of salt (alkali conjugation)Ka = constant acidn = valence saltExamples of CH3COOH to CH3COONa mix.b. Alkaline buffer solution (a mixture of weakly basic and konjugasinya acid or salts of weak bases)
[OH-] = Kb x [B]
                      n x [G]

Description:[B] = concentration of weakly basic[G] = concentration of salt (acid conjugation)Kb = constant basen = valence saltExample of a mixture of NH4OH and NH4Cl.B. HydrolysisHydrolysis is the decomposition reaction with the ions of weak acid and weak base in water. Produced ions form H + and OH-to the salt solution may be acidic or alkaline.Based on constituent, salt differentiated into 4 as follows.a. Salts of strong acids and strong basesSalts of strong acids and strong bases are not hydrolyzed until neutral, pH = 7. Examples NaCl derived from strong bases NaOH and strong acid HCl.b. Salt of strong acid and weak baseSalt of strong acid and weak base will partially hydrolyzed, are acidic, and a pH <7.

[H +] = (Kw / Kb) 1/2. M


NH4Cl example derived from weakly basic NH4OH and strong acid HCl.c. Salts of weak acids and strong basesSalts of weak acids and strong bases partially hydrolyzed, alkaline, and a pH> 7.


[OH-] = (Kw / Ka) 1/2. M
Examples of CH3COONa CH3COOH derived from weak acids and strong bases NaOH.d. Salt of weak acid and weak baseSalts of weak acids and weak bases are hydrolyzed perfect and the price varies pH Ka and Kb.
[H +] = {(Kw. Ka) / Mb} 1/2

Examples CH3COONH4 derived from weak acid CH3COOH and NH4OH weakly basic.In brief, a mixture of acid and alkaline pH can be determined in the following manner.a. If there is no waste then used the formula pH salt.b. If there is a weak waste then used the formula pH buffer.c. If there is a strong residual waste then used a strong pH formula (ionized).