The correct options are
B 0.003 moles of calcium oxalate will get precipitated.
C Ca(NO3)2 is the excess reagent.
D Na2C2O4 is the limiting reagent.
Ca(NO3)2100×0.06=6mmol+Na2C2O450×0.06=3mmol→CaC2O4↓−3mmol=0.003mol+2NaNO3
Na2C2O4 is the limiting reagent.
∴3mmolNa2C2O4=3mmolCa(NO3)2
≡3mmolCaC2O4≡6mmolNaNO3
mmol of Ca(NO3)2 left=6−3=3mmol=0.003mol
MCa2+(left)=3mmol(100+50)mL=3150=0.02M
Therefore, option B is wrong.
Hence, options A,C and D are correct.