Write the balanced molecular equation for the neutralization reaction between HI and Ba(OH)2 in aqueous solution. Include physical states.
The Correct Answer and Explanation is:
Balanced Molecular Equation:
2HI(aq)+Ba(OH)2(aq)→BaI2(aq)+2H2O(l)2HI(aq) + Ba(OH)_2(aq) \rightarrow BaI_2(aq) + 2H_2O(l)2HI(aq)+Ba(OH)2(aq)→BaI2(aq)+2H2O(l)
Explanation (300 words, without using the word “we”):
The reaction between hydroiodic acid (HI) and barium hydroxide Ba(OH)2\text{Ba(OH)}_2Ba(OH)2 represents a typical acid-base neutralization. Hydroiodic acid is a strong acid that completely dissociates in aqueous solution into hydrogen ions (H⁺) and iodide ions (I⁻). Barium hydroxide is a strong base that also dissociates fully in water to release barium ions (Ba²⁺) and hydroxide ions (OH⁻).
In a neutralization process, hydrogen ions from the acid react with hydroxide ions from the base to form water, a neutral and stable product. The number of H⁺ ions must be balanced with the number of OH⁻ ions to ensure complete neutralization. Each molecule of barium hydroxide provides two hydroxide ions, while each molecule of hydroiodic acid provides one hydrogen ion. Therefore, two moles of HI are required to neutralize one mole of Ba(OH)₂.
The reaction produces barium iodide (BaI₂) as a salt. Barium iodide is soluble in water and remains in the aqueous phase as dissociated Ba²⁺ and I⁻ ions. The reaction also forms two molecules of water as a result of the combination of two H⁺ and two OH⁻ ions.
The physical states are included to show the nature of each substance during the reaction. Both HI and Ba(OH)₂ are aqueous, indicating they are dissolved in water. The product BaI₂ is also aqueous, confirming its solubility, and water is produced as a liquid.
Neutralization reactions such as this are fundamental in acid-base chemistry. They are commonly used in laboratory titrations to determine the concentration of unknown acid or base solutions. The predictable formation of water and a salt makes these reactions essential for various industrial and chemical applications.
