Answer:
Observation X: The aqueous potassium iodide solution becomes yellow in color
Observation Y: A clear, colorless solution is observed.
Explanation:
Experiment 1
When Concentrated sulfuric acid is added to potassium chloride, hydrogen chloride gas is produced:
H₂SO₄ + 2KCl ⇒ 2HCl (g) + K₂SO₄
When the HCl gas is bubbled into aqueous potassium iodide, a redox reaction takes place at room temperature when energy is provided in the form of light:
4H⁺ + 4I⁻ + O₂ ⇒ 2I₂ + 2H₂O
The iodine causes the solution to become yellow in color (or darker yellow/brown at high concentrations of iodine).
Experiment 2:
When potassium chloride in aqueous ammonia is added to aqueous silver nitrate, the following net reaction occurs:
Ag⁺ + 2NH₃ ⇒ [Ag(NH₃)₂]⁺
The silver reacts with ammonia rather than chloride as ammonia is a better ligand in this case. The ammonia complex is soluble in water.
Thus, a clear, colorless solution will be observed.
