Here's how to write the balanced equation for the reaction of iron(II) hydroxide (Fe(OH)₂) and phosphoric acid (H₃PO₄):

1. Write the Unbalanced Equation:

Fe(OH)₂ + H₃PO₄ → Fe₃(PO₄)₂ + H₂O

2. Balance the Iron (Fe) Atoms:

* There are 3 Fe atoms on the right side and only 1 on the left.

* Multiply Fe(OH)₂ by 3: 3Fe(OH)₂ + H₃PO₄ → Fe₃(PO₄)₂ + H₂O

3. Balance the Phosphate (PO₄) Groups:

* There are 2 PO₄ groups on the right side and only 1 on the left.

* Multiply H₃PO₄ by 2: 3Fe(OH)₂ + 2H₃PO₄ → Fe₃(PO₄)₂ + H₂O

4. Balance the Hydrogen (H) Atoms:

* There are 12 H atoms on the left side (6 from Fe(OH)₂ and 6 from H₃PO₄) and 2 on the right.

* Multiply H₂O by 6: 3Fe(OH)₂ + 2H₃PO₄ → Fe₃(PO₄)₂ + 6H₂O

5. Balance the Oxygen (O) Atoms:

* There are 14 O atoms on both sides, so the oxygen is already balanced.

The Balanced Equation:

3Fe(OH)₂ + 2H₃PO₄ → Fe₃(PO₄)₂ + 6H₂O