Chapter 15.1, Problem 6RQ

Interpretation Introduction

Interpretation: Effect of stirring, surface area and heating on number of collisions between solid and solvent particles has to be explained.

Concept introduction: Solution is mixture in which all components are uniformly distributed. Any solution has 2 substances: solute and solvent. For formation of solution compatibility between solute and solvent is required. Example is salt solution and sugar solution.

On the basis of quantity of solute in a specified amount of solvent, solutions are called dilute or concentrated.

Answer to Problem 6RQ

Stirring, higher surface area and heating increases the number of collisions and hence rate of dissolution.

Explanation of Solution

The factors that determine the rate at which a solid solute can get dissolved in a liquid solvent are: surface area, stirring and heating or temperature.

Higher the surface area, higher will be the rate of dissolution as more area of solute will be exposed for interaction with solvent.

Stirring helps in removing the newly dissolving surface of solid solute so that fresh surface can interact with solvent for dissolution. Also it increases random movement of solvent and solute molecules.

Higher heating will increase the number of collisions between solvent and solute molecules by increasing the rapid movement of solvent. High temperature imparts thermal energy to solvent and fastens the process of dissolution.

Conclusion

Stirring, higher surface area and heating increases the number of collisions and hence rate of dissolution.