By crushing the solute to smaller pieces the amount of surface area for the solute to contact the solvent INCREASES.

The more solute/solvent interactions that occur the faster will be the rate of dissolution!

This is why Kool-aid is such a fine powder!

***Important to note that molecular bonds are NOT being broken, the molecules are just in smaller pieces.

Size of solute - explained

Agitation - Recap

Stirring or agitating a solution increases the amount of solute/solvent interactions mechanically.

Increasing solute/solvent interactions increases rate of dissolution.

This is why you stir the Kool-aid when you add it to the water.

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This video is about How TEMPERATURE affects the rate of dissolution.

Temperature - Recap

• Increasing kinetic energy (energy of motion) increases the number of solute/solvent interactions.

• Increasing the number of solute/solvent interactions increases the rate of dissolution.

• AGAIN NOTE that for gases, they are actually more soluble in liquids at lower temperatures, because they boil out when the temperature is too high.

​Exemplar

Heating a solution increases the kinetic energy of the solution. This will increase the rate of dissolution, because the solute and solvent will be interacting or "bumping" in to each other more, causing the solute to dissolve more quickly.

Big Idea

To increase the rate of dissolution, you can:

-stir

-crush the solute

-heat the solution

Why do these all work? It is all about increasing solute-solvent interactions. The more the solute and solvent interact, the more quickly the solute will dissolve.

Stirring manually makes the solute and solvent bump into each other more.

Crushing the solute creates more surface area of solute to bump into the solvent more.

Heating the solution increases the kinetic energy of the solution, which means the solute and solvent will be moving around more and will bump into each other more.

Exemplar...

​The flavor packets have very small, fine pieces of solute (flavoring). That creates a lot of surface area for dissolution. You place the flavoring in hot water and stir, which also contributes to the quick dissolution of the flavor packet.