Assume that a student added to much NH3 and that as a result

Assume that a student added to much NH3 and that as a result some MGC2O4 precipitated. Will that make it seem that there is more or less calcium than there was?

Solution

Assuming a student added to much NH3 and that resulted into some MgC2O4 precipitation.

This would make it seem that the there is less amount of calcium in the solution.

Ksp of CaC2O4 is much lower than the Ksp of MgC2O4, that is until all of CaC2O4 is precipitated out first from the solution no MgC2O4 would precipitate out. When CaC2O4 is precipitating, all of MgC2O4 is in solution. MgC2O4 has higher solubility than CaC2O4.