Chemical formula of magnesium phosphate is

Question

Accepted Answer

The chemical formula of magnesium phosphate is correctly given as Mg_3(PO_4)_2, which is Option 3. Let's explore why this is the correct answer and why the other options are incorrect.

### Explanation for Option 3: Mg_3(PO_4)_2

1. **Valency Consideration**: Magnesium (Mg) has a valency of +2, while the phosphate ion (PO_4) has a valency of -3. To balance the charges between magnesium and phosphate, we need three magnesium ions to balance the charge of two phosphate ions. This results in the formula Mg_3(PO_4)_2.

2. **Charge Balance**: The total positive charge from three Mg^2+ ions is +6, and the total negative charge from two PO_4^3- ions is -6. These charges balance each other out, resulting in a neutral compound.

### Explanation for Incorrect Options

1. **Option 1: MgPO_4**
   - This formula suggests a 1:1 ratio between magnesium and phosphate ions. However, this does not balance the charges, as Mg^2+ and PO_4^3- would not result in a neutral compound. The charges would be +2 and -3, respectively, leading to an imbalance.

2. **Option 2: Mg_2(PO_4)_3**
   - This formula implies two magnesium ions for three phosphate ions. The total positive charge would be +4 (from two Mg^2+ ions), and the total negative charge would be -9 (from three PO_4^3- ions). This results in an imbalance, as the charges do not cancel each other out.

3. **Option 4: Mg(PO_4)_2**
   - This formula suggests one magnesium ion for two phosphate ions. The total positive charge would be +2 (from one Mg^2+ ion), and the total negative charge would be -6 (from two PO_4^3- ions). This also results in an imbalance, as the charges do not neutralize.

In conclusion, Option 3, Mg_3(PO_4)_2, is the correct chemical formula for magnesium phosphate because it accurately reflects the charge balance between magnesium and phosphate ions, resulting in a stable, neutral compound.