Question

A solution is saturated with silver sulfate and contains excess solid silver sulfate: Ag₂SO₄() ⇌ 2Ag + () + SO₄²- ()

A small amount of solid silver sulfate containing a radioactive isotope of silver is added to this solution. Within a few minutes, a portion of the solution phase is sampled and tests positive for radioactive Ag+ ions. Explain this observation.

Answer 1

The presence of radioactive Ag+ ions in a saturated solution of silver sulfate is due to the dynamic nature of solubility equilibrium, where solid silver sulfate and its ions are in a constant state of dissolution and precipitation.

Step-by-step explanation:

The observation that a solution saturated with silver sulfate tests positive for radioactive Ag+ ions after a small amount of silver sulfate containing a radioactive isotope of silver is added can be explained by the nature of a solubility equilibrium.

Despite the solution being saturated, the equilibrium demonstrates the dynamic process where the solid silver sulfate continuously dissolves into Ag+ and SO42- ions at the same rate that these ions precipitate and reform solid silver sulfate.

When the radioactive silver sulfate is added, some of its silver ions dissolve and become part of the equilibrium, thereby becoming detectable in the solution.