Final answer:
The correct formula for iron(II) phosphate is (A) Fe₃(PO₄)₂. This formula is derived by finding the least common multiple of +2 and -3, the charges of iron(II) and phosphate ions, to balance the charges, resulting in a neutral compound.
Step-by-step explanation:
The formula of iron(II) phosphate is Fe₃(PO₄)₂, which corresponds to option a). To determine the correct formula, we should look at the charges of the ions involved.
Iron(II) has a charge of 2+ and the phosphate ion (PO₄³-) has a charge of 3-. Since neither charge is an exact multiple of the other, we need to find a common multiple that would balance the charges in the compound. The least common multiple of the charges +2 and -3 is 6.
Therefore, to get a charge of 6+, we need three iron(II) ions, and to achieve a charge of 6-, we require two phosphate ions. Combining three Fe²+ ions with two PO₄³- ions yields a neutral compound with the formula Fe₃(PO₄)₂, the name of which is iron(II) phosphate.