Which statement is true about the value of Qs in a saturated solution?

In a saturated solution, the value of Qs, which is the reaction quotient for the dissolution of a sparingly soluble salt, is equal to Ks, the solubility product constant at a given temperature. This equality occurs because, in a saturated solution, the system has reached a state of dynamic equilibrium. At this point, the rates of dissolution and precipitation of the solute are equal, meaning that the concentration of the dissolved ions is stable and reflects the maximum capacity of the solvent to hold those ions at the given temperature.

The relationship between Qs and Ks is fundamental in understanding solubility equilibria; when Qs equals Ks, it indicates that the system is saturated. If Qs were greater than Ks, it would suggest that the solution is supersaturated and that precipitation would occur. Conversely, if Qs were less than Ks, it would imply that the solution is unsaturated and more solute could still dissolve. This understanding of Qs and Ks is crucial for predicting the behavior of salts in solution, especially in applications related to solubility and precipitation reactions.