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Pure and impure substances

Dissolving a mixture

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Explainer Video

Tutor: Alisha

Summary

Dissolving a mixture

In a nutshell

Dissolving is when solutes mix with a solvent to give a solution.

Definitions

Key word	Definition
Dissolving	When a solid is being incorporated into a liquid.
Solute	The solid being dissolved.
Solvent	The liquid the solid is dissolving into.
Solution	A mixture of solute and solvent.
Soluble	A substance that dissolves.
Insoluble	A substance that does not dissolve.
Saturated solution	A solution which will not dissolve any more solute at a given temperature.
Solubility	The measure of how much solute will dissolve in a given solvent.
Kinetic energy	The energy an object has because of its movement.

What happens during dissolving?

When you add a solute to a solvent the bonds in solute particles can sometimes break. These solute particles go onto interact and 'mix' with the solvent particles, forming a solution.

The solute does not vanish - it is still there. This can be confirmed by evaporating the solvent and what you will find is the solute left behind.

Example

Add $10\,g$  of sugar (solute) to $100\,g$  of water (solvent). You will form a solution with a mass of $110\,g$ . There is no reduction in mass.

1.	Solute
2.	Solvent
3.	Dissolving
4.	Dissolved

Solubility

Increasing the temperature leads to more solute dissolving in the solvent. This is because the particles will have a greater kinetic energy, therefore able to dissolve easily.

Keep in mind that certain solutes will not dissolve in certain solvents.

Example

Salt does not dissolve in petrol.

Learn with Basics

Length:

Unit 1

Changes of state

Unit 2

Reversible changes and separation methods

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Optional

Unit 3