I am really struggling here :confused:

What type of componds are Ammonium Oxalate and Calcium Oxalate? How are the individual compounds bonded? In a reaction of ammonium oxalate and calcium ions, the calcium ions dispace the ammonium ions, why and how do they do this?

Thanks in anticipation of your help!

Ammonium Oxalate is ionic. Ammonium is NH_4^+. Calcium is Ca^{2+}, Oxalate is [math]C_2O_4^{2-}.

Ammonium oxalate:

(NH_4)_2 C_2O_4 \rightleftharpoons 2NH4^+ + C_2O_4^{2-}

Calcium Oxalate:

CaC_2O_4 (s) \rightleftharpoons Ca^{2+} + C_2O_4^{2-}

Note that calcium oxalage is very insoluble in water, so the equilibrium shown above lies far to the left. Ammonium oxalate is much more soluble in water. Therefore, the calcium will grab the oxalate ion and precipitate out.