Identify the reactants and products in the chemical equation: Barium hydroxide (Ba(OH)₂) and nitric acid (HNO₃) are the reactants, while barium nitrate (Ba(NO₃)₂) and water (H₂O) are the products.
Write the unbalanced chemical equation: Ba(OH)₂(aq) + HNO₃(aq) → Ba(NO₃)₂(aq) + H₂O(l).
Count the number of each type of atom on both sides of the equation. Initially, you have 1 Ba, 2 OH, 1 H, and 1 NO₃ on the reactant side, and 1 Ba, 2 NO₃, and 2 H (from H₂O) on the product side.
Balance the equation by adjusting coefficients. Start by balancing the nitrate ions (NO₃). You need 2 NO₃ on the reactant side, so place a coefficient of 2 in front of HNO₃: Ba(OH)₂(aq) + 2 HNO₃(aq) → Ba(NO₃)₂(aq) + H₂O(l).
Check the balance of hydrogen and oxygen atoms. You now have 2 H from 2 HNO₃ and 2 OH from Ba(OH)₂, which combine to form 2 H₂O. Adjust the coefficient of H₂O to 2 to balance the equation: Ba(OH)₂(aq) + 2 HNO₃(aq) → Ba(NO₃)₂(aq) + 2 H₂O(l).