Final answer:
The correct balanced chemical equation for the reaction between H₂CrO₄ and Ba(OH)₂, considering the formation of CrO₄²− in a basic medium, is represented by option (d).
Step-by-step explanation:
The reaction provided by the student is between the acid H₂CrO₄ (chromic acid) and Ba(OH)₂ (barium hydroxide), which is a base. When an acid reacts with a base, the products are typically a salt and water - a reaction known as neutralization. However, it seems the student is also considering the formation of chromate ions (CrO₄²−), which can occur in a basic environment. Given the information provided and the fact that the reaction occurs in a basic medium as implied by the presence of OH− ions, we need to properly balance the chemical equation.
Looking at the options provided:
- Option (a) doesn’t balance the chromium species and hydroxide ions correctly.
- Option (b) has an excess of H₂CrO₄− ions and hydroxide ions.
- Option (c) has an excess of water molecules.
- Option (d) provides a properly balanced equation with respect to all species, assuming dichromate and chromate equilibria are not considered in this context.
Therefore, the correct answer is:
d. H₂CrO₄ + Ba(OH)₂ → 2H₂CrO₄− + 2OH− + 2CrO₄− + 2H₂O