Balance the equation: Ba (OH) 2 (aq) + H3PO4 (aq)

The products of the unbalanced reaction are as follows:

Ba (OH) ₂ (aq) + H₃PO₄ (aq) → Ba₃ (PO₄) ₂ (s) + H₂O (l)

This is an acid base reaction where Ba (OH) ₂ is the base and H₃PO₄ is the acid. Acid base reaction is also known as neutralization reaction where the acid and base react with each other to form salt and water. In this reaction Ba₃ (PO₄) ₂ is the salt. Also barium phosphate (Ba₃ (PO₄) ₂) is insoluble in water and forms a solid precipitate.

The balanced reaction is as follows:

3Ba (OH) ₂ (aq) + 2H₃PO₄ (aq) → Ba₃ (PO₄) ₂ (s) + 6H₂O (l)

There are three Ba from Ba₃ (PO₄) ₂ on the product side of the equation, so to balance 3 coefficient was placed before Ba (OH) ₂. Similarly, 2 coefficient was placed before H₃PO₄ on the reactant side to balance the two phosphate from Ba₃ (PO₄) ₂ on the product side. Finally, 6 coefficient was placed before H₂O on the product side, to balance the number of H and O atoms on both side of the equation.