Final answer:
The solubility of KBr in an aqueous solution does not change significantly with a decrease in pressure since pressure effects are more pertinent to the solubility of gases than solids or liquids.
Step-by-step explanation:
When pressure is decreased on an aqueous solution of KBr, the solubility of KBr is not significantly affected. This is because pressure changes have very little effect on the solubility of solids or liquids; they are more influential on the solubility of gases. For gases, an increase in pressure corresponds to an increase in solubility in a liquid due to more frequent collisions of the gas molecules with the gas-liquid boundary.
Conversely, a decrease in pressure results in decreased gas solubility, as seen when carbon dioxide escapes from an opened soda can. However, in the case of solutes like KBr, which is solid, the solubility product (Ksp) is more relevant. Ksp is an expression that relates the equilibrium concentrations of ions in a saturated solution. The common ion effect is another aspect that can affect solubility, wherein the addition of a common ion to a solution can decrease the solubility of a salt.