Which of the following is the correct formula for manganese(III) sulfate?
a. MnSO4
b. Mn2(SO4)3
c. Mn(SO4)2
d. Mn3(SO4)2
e. Mn2804
The correct answer and explanation is :
The correct formula for manganese(III) sulfate is:
b. Mn₂(SO₄)₃
Explanation (Approx. 300 words):
To determine the correct chemical formula of manganese(III) sulfate, we need to consider the charges of the ions involved.
- Manganese(III) means manganese has a +3 oxidation state, so the cation is Mn³⁺.
- Sulfate is a polyatomic anion with the formula SO₄²⁻ and a charge of -2.
We now need to combine Mn³⁺ and SO₄²⁻ in such a way that the compound is electrically neutral. This means the total positive charge must equal the total negative charge.
Let’s find the least common multiple (LCM) of the charges:
- Mn³⁺ has a +3 charge.
- SO₄²⁻ has a –2 charge.
- The LCM of 3 and 2 is 6.
To get a total charge of +6, you need 2 Mn³⁺ ions:
- 2 × (+3) = +6
To get a total charge of –6, you need 3 SO₄²⁻ ions:
- 3 × (–2) = –6
So, to balance the charges, you need 2 manganese(III) ions and 3 sulfate ions, resulting in the formula:
➡ Mn₂(SO₄)₃
Why the Other Options Are Incorrect:
- a. MnSO₄ – Manganese is in the +2 state here; this is manganese(II) sulfate.
- c. Mn(SO₄)₂ – Implies manganese is in the +4 state (Mn⁴⁺), which is incorrect for manganese(III).
- d. Mn₃(SO₄)₂ – This matches a +2 manganese ion (3 × +2 = +6, 2 × –2 = –4 → unbalanced).
- e. Mn2804 – Not a valid formula; likely a typographical error.
Thus, the correct and chemically balanced formula for manganese(III) sulfate is:
✅ b. Mn₂(SO₄)₃