The formula for copper(II) phosphate is A. CuPO4. B. Cu2(PO4)3. C. Cu2(PO4)3. D. Cu3(PO4)2. E. Cu3(PO4)2.
The Correct Answer and Explanation is:
The correct formula for copper(II) phosphate is D. Cu3(PO4)2.
Explanation:
Copper(II) phosphate is a compound that consists of copper in the +2 oxidation state and the phosphate ion, PO4^3-. The Roman numeral II in copper(II) indicates that copper has a +2 charge. The phosphate ion (PO4) has a -3 charge. To balance the charges between copper and phosphate, we need to combine copper and phosphate ions in a way that the overall charge of the compound is neutral.
- Copper ion (Cu²⁺): Each copper ion carries a +2 charge.
- Phosphate ion (PO₄³⁻): Each phosphate ion carries a -3 charge.
To balance the charges:
- Three copper ions (3 × +2 = +6 charge) will balance two phosphate ions (2 × -3 = -6 charge).
- This results in the neutral compound, Cu3(PO4)2.
Thus, the correct formula is Cu3(PO4)2, meaning there are three copper ions for every two phosphate ions in the compound.
Why the other options are incorrect:
- A. CuPO4: This formula suggests one copper ion (Cu²⁺) with one phosphate ion (PO₄³⁻), but the charges do not balance because +2 and -3 cannot form a neutral compound in a 1:1 ratio.
- B. Cu2(PO4)3: This formula implies that two copper ions would balance three phosphate ions. This would result in a total charge of +4 from copper and -9 from phosphate, which is unbalanced.
- C. Cu2(PO4)3 (duplicate of B). Same as option B, incorrect for the same reason.
- E. Cu3(PO4)2 (same as D). This is the correct answer, already explained above.
Therefore, the answer is D. Cu3(PO4)2.
