Consider the insoluble compound cobalt(II) hydroxide , Co(OH)2 . The cobalt(II) ion also forms a complex with ammonia . Write a balanced net ionic equation to show why the solubility of Co(OH)2 (s) increases in the presence of ammonia and calculate the equilibrium constant for this reaction.

4.56×10^-10

Explanation:

Co(OH)2(s)<>Co^2+(aq) + 2OH^-(aq)

Co^2+(aq) + 6NH3(aq) >[Co(NH3)6]^2+(aq)

Overall equation:

Co(OH)2(s)+ 6NH3(aq) >[Co(NH3)6]^2+(aq) + 2OH^-(aq)

The increased solubility of the cobalt salt in the presence of ammonia is as a result of the formation of the hexammine cobalt II complex shown above.

Knet= Ksp×Kf

Ksp of Co(OH)2= 5.92 × 10^-15.

Kf= 7.7 x 10^4

Knet= 5.92 × 10^-15 × 7.7 x 10^4

Knet= 4.56×10^-10

Note Knet is the equilibrium constant of the overall reaction.

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.