Zn2+ and PO43- make Zn3(PO4)2, Right? im assuming its called zinc(II) phosphate. or is it zinc phosphate because zinc is always +2 in compounds? I just need someone to check my work!
The Correct Answer and Explanation is:
Yes, Zn²⁺ and PO₄³⁻ combine to form Zn₃(PO₄)₂, and the correct name is zinc phosphate, not zinc(II) phosphate. Here’s the explanation:
✅ Correct Compound: Zn₃(PO₄)₂
To determine the formula:
- Zinc ion is Zn²⁺.
- Phosphate ion is PO₄³⁻.
To balance the charges:
- You need 3 Zn²⁺ (total +6) and 2 PO₄³⁻ (total -6) to neutralize each other.
- So the formula is Zn₃(PO₄)₂.
✅ Correct Name: Zinc Phosphate
Now, naming:
Zinc is a transition metal, but it’s an exception in nomenclature. While many transition metals can have multiple oxidation states (and therefore need Roman numerals in naming), zinc almost always forms a +2 ion, just like how silver is nearly always +1.
Thus, even though zinc is a transition metal, it forms only one common ion (Zn²⁺). According to IUPAC naming conventions, you don’t need to include the oxidation number in the name if the metal only has one common charge.
- “Zinc phosphate” is correct and sufficient.
- “Zinc(II) phosphate” is technically not incorrect, but it’s redundant and not the preferred name.
🔍 Summary:
- Formula: Zn₃(PO₄)₂
- Name: Zinc phosphate
This distinction is important in chemistry, especially for transition metals. For example:
- Fe²⁺ and Fe³⁺ form different compounds: iron(II) and iron(III).
- But Zn²⁺ always forms zinc compounds, so no Roman numeral is needed.
