I'm a bit confused is this the formula for Copper III Tartrate: Cu2 (C4H4O6)3OR is it Cu(C4H4O6)3And if it is the second one then why is it that one?Also, Why is Zinc Phosphate's formula Zn3(PO4)2 and not Zn3PO4
I'm half certain that the first one is the correct formula. Compounds must balance each other out ionically to be stable so you have to bear in mind the valency of each half. Copper ions have a valency of +3 and Tartrates have a valency of -2. To make the ionic formulae balance you need 2 Copper ions to bond giving you +6 and therefore 3 Tartrate ions to bond giving -6. This way they balance out and you have the stable formula Cu2 (C4H4O6)3. The answer to your second question is much the same. The valency of (Zn) ion is 2 and that of Phosphate is -3. The valencies are balanced by using 3 (Zn) and 2 Phosphate i.e. Zn3 PO4(2)
