Equal volumes of 0.002 M solutions of sodium iodate and cupric chlorate are mixed together. Will it lead to precipitation of copper iodate? (For cupric iodate Ksp = 7.4 × 10–8).

Given:

Ksp of cupric iodate = 7.4 × 10–8


Equal volumes of 0.002 M solutions of sodium iodate and cupric chlorate are mixed together.


Ionization of sodium iodate:


2NaIO3 + CuCrO4 Na2CrO4 + Cu(IO3)2


After mixing, [NaIO3] = [IO3-] = = 10-3M


[CuCrO4] = [Cu2+] = = 10-3M


For cupric iodate, the ionization is:


Cu(IO3)2 [Cu2+][IO3-]


As we know that,


Ksp = [A+] [B-]


Where A and B are the ions dissolved


In the above reaction,


[A+] = [Cu2+]


[B-] = [IO3-]


Ksp = [Cu2+][IO3-]


Ksp = (10-3)(10-3)


Ksp = 10-9


As we know that precipitation only occur when Ksp < [A+][B-]


As ionic product 10-9 is less than the Ksp (7.4 × 10–8), hence no precipitation will occur.


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