Question

The pH's of eight 0.1M aqueous salt solutions are given below. Write the hydrolysis equation(s) for each. (Several will have more than one equation.) If no hydrolysis reaction takes place, write N.R. Here are the salt solution with thier pH

a) sodium acetate pH 9 e) sodium sulfate pH 7 b) sodium carbonate pH11 f) sodium bisulfate pH2 c) ammonium chloridepH 5 g) sodium nitrite pH8 d) sodium chloride pH 7 h) sodium bicarbonate pH 9

Answer 1

Let Ac be the acetate, i.e. CH3COO- be "Ac-" then

a)

NaAc --> Na+ + Ac-

Ac- + H2O <--> HAc + OH-

b)

Na2CO3 = 2Na+ CO3-2

CO3-2 + H2O <> HCO3- + OH-

HCO3- + H2O <> H2CO3- + OH

c) NH4Cl = NH4+ + Cl-

NH4+ + H2O <> NH3 + H3O+

d)

NR; i.e. NaCl = Na+ + Cl-

e)

Na2SO4 <--> 2Na+ + SO4-2

NR; since H2SO4 is storng acid

f)

NaHSO3 = Na+ + HSO3-

HSO3- + H2O <> H2SO3 + OH

g)

NaNO2 = Na+ + NO2-

NO-2 + H2O <> HNO2 + OH-

h)

NaHCO3 = Na+ + HCO3-

HCO3- + H2O <> H2CO3 + OH-