Q . concentration of Ag+ ion in saturated solution of Ag2C2O4        is 2.2*10^-4 mol/lit . solubility product ofAg2C2O4 is 

     1.  4.5*10^-11      2. 5.3*10^-12   3. 2.42*10^-8  

      4.  2.66*10^-12