Question

Which of the following can function as a chelating agent? And Why?
a. NH3
b. CO2
c. OH-
d. C2O4 2-

Answer 1

In oxalate,  you need have to have two donor atoms to make a chelate ligand which barely means, NH3 and OH^- is ruled out. You have to consider the structure of Carbon dioxide (CO2) and deduce why both O atoms cannot coordinate to the same M^n+ ion.