Which of the following would increase the rate of dissolution of a solid in a solution? 1) Cool the solid and the solution 2) Cool only the solid 3) Dry up the solvent 4) Stir the solid and solution
The Correct Answer and Explanation is :
The correct answer is 4) Stir the solid and solution.
Explanation:
The rate of dissolution refers to how quickly a solid solute dissolves in a solvent to form a solution. Several factors can influence this rate:
- Temperature: Generally, increasing the temperature of a solution speeds up the dissolution process because it increases the kinetic energy of the molecules. This leads to more frequent and energetic collisions between the solute and solvent molecules. Cooling the solid or the solution (as in options 1 and 2) would reduce the kinetic energy and slow down the dissolution.
- Concentration of solvent (drying up the solvent): If you dry up the solvent, there is less solvent available to interact with the solute, which would decrease the dissolution rate. This eliminates option 3 as a valid choice for increasing the dissolution rate.
- Stirring: Stirring the solution helps distribute the solute particles more evenly throughout the solvent. It increases the frequency of collisions between solute and solvent molecules, which facilitates faster dissolution. The movement caused by stirring prevents the solute from forming a saturated region near the surface, allowing fresh solvent to come in contact with the solute more quickly. Therefore, stirring enhances the rate of dissolution (as stated in option 4).
In summary, stirring the solid and solution (option 4) promotes a higher dissolution rate by ensuring more effective mixing and increasing the frequency of molecular collisions. On the other hand, cooling the system or reducing the solvent would slow the process down.