Question

What are the (1) Net ionic equation for hydrolysis, (2) equilibrium expression and (3) Ka or Kb for each of these solutions:

Na2CO3

NaC2H3O2

NH4Cl

ZnCl2

KAI(SO4)2

Answer 1

Na2CO3 undergoes hydrolysis.Na2CO3 has a Kb of 2.1×10^-4.

Na2CO3 +H2O=NaOH+NaHCO3

CO₃^2-+H₂O=HCO₃^-+OH^-

NaC2H3O2

NaC2H3O2+H2O=NaOH+ CH3COOH

C₂H₃O₂^-+H₂O=CH₃COOH+OH^-

Ka is 1.8×10^-5.

NH4Cl+H2O=H₃O⁺+ NH3+Cl^-

NH₄⁺+H₂O=NH₃+H₃O⁺

Ka is 5.6×10^-10.

ZnCl2

ZnCl2+2H2O=Zn(OH)2+2HCl

Zn²⁺+2H₂O=Zn(OH)₂+2H⁺

ZnCl2 Ka is 2.5×10^-10.

KAl(SO4)2=K⁺+Al³⁺+2SO₄^2-

Al³⁺+4H₂O=Al(OH)₄+4H⁺

For SO₄^2- Ka is 1.2×10^-2.