The Barium hydroxide solution is prepared by dissolving 3.40g of Ba (OH)2 in water to make 68.6mL of solution.

Question

The barium hydroxide solution is used to titrate a perchloric acid solution of unknown concentration. How do you write a balanced chemical equation to represent the reaction between barium hydroxide and perchloric acid?

Answer 1

Barium hydroxide is Ba(OH)₂ and perchloric acid is HClO₄, so those would be your two reactants. This is a double replacement reaction where the cations (Ba⁺² and H⁺) switch places, so the products would be barium perchlorate (Ba(ClO₄)₂) and hydrogen hydroxide (HOH) otherwise known as water. I find that it helps to write water as HOH when you are balancing the equation.

Your skeleton equation (before you balance) would look like this:

Ba(OH)₂ + HClO₄ → Ba(ClO₄)₂ + HOH

2 perchlorate ions on the left mean you need 2 perchloric acids on the right:

Ba(OH)₂ + 2 HClO₄ → Ba(ClO₄)₂ + HOH

Now you have 2 H+ ions and 2 OH- ions on the right, so you need 2 HOH on the left.

Ba(OH)₂ + 2 HClO₄ → Ba(ClO₄)₂ + 2 HOH

Turning your water back into H₂O, you have:

Ba(OH)₂ + 2 HClO₄ → Ba(ClO₄)₂ + 2 H₂O