what is the concentration of the oxalate ion when the first cation begins to precipitate

Question

vincent-lyon.fr · Answer

What cation(s) do you have?  $Ca^{2+}$ and $Mg^{2+}$

There's some missing information there.

anonymous · Answer

sorry haha the other part is:
If a solution contains 0.01 M Ca2+ and 0.01 M NI2+ ions and you want to separate them using aqueous (NH4)2C2O2, which ion will precipitate first as an oxalate, Cac2o4 or Nic2O4?
Ksp CaC2O4=4.75 X 10^-4
Ksp NiC2O4=4.0 X 10^-10

cherylim23 · Answer

Since Ksp of CaC2O4 > Ksp of NiC2O4, CaC2O4 is more soluble than NiC2O4 and Ni2+ will precipitate first.