Starter quiz
- Which of the following statements is true of a solution?
- It has particles that are visible to the naked eye.
- It is made of two or more substances mixed evenly at the particle level. ✓
- It separates into layers when left standing.
- It can only be made with liquids.
-
- Arrange the following states of substances based on their increasing ability to flow, starting with the state that cannot flow.
- 1⇔Substances in the solid state.
- 2⇔Substances in the liquid state.
- 3⇔Substances in the gas state.
- ______ is the ability of a substance to dissolve in a solvent.
- 'solubility' ✓
- Match the term with its description.
- Solvent⇔A substance into which a solute dissolves. ✓
- Solute⇔A substance that has dissolved into a solvent. ✓
- Solution⇔When a solute and solvent combine, this is formed. ✓
- Soluble⇔When a solute dissolves, it is described as this. ✓
- What happens to the total mass of substances that are mixed together?
- They lose mass.
- They gain mass.
- Their total mass stays the same. ✓
- Their total mass is halved.
-
- What is the term for the random motion of particles suspended in a medium?
- 'brownian motion' ✓
Exit quiz
- Why is a suspension not considered a solution?
- It has a fixed melting point.
- Solid particles are visible and can settle. ✓
- It changes state over a range of temperatures.
- It contains impurities.
-
- Match the term with its characteristic.
- Solubility⇔Ability to dissolve in a solvent. ✓
- Dissolving⇔Overcoming forces of attraction between solvent particles. ✓
- Melting⇔Changing from a solid to a liquid state. ✓
- Dissolving is not the same as melting, but both are ______ processes.
- 'physical' ✓
- Why is it incorrect to say that every substance can be dissolved in a solvent?
- Lack of stirring.
- Differences in solubility. ✓
- High temperature.
- Presence of impurities.
-
- During the dissolving process, why does a solute dissolve in a solvent?
- Solute-solvent forces of attraction are weaker than solute-solute.
- The solute particles are larger than the solvent particles.
- Solute-solvent forces of attraction are stronger than solute-solute. ✓
- The solute particles do not collide with the solvent particles.
-
- Why might the total volume of a mixture be less than the sum of the volumes of its individual components?
- Evaporation occurs.
- Particles fit into spaces between each other. ✓
- Chemical reaction reduces volume.
- Measurement error.
- Some solvent is spilled when forming the mixture.
-
Worksheet
Presentation
Video
Lesson Details
Key learning points
- Suspensions are not solutions, as solid particles can be seen, and eventually will settle over time.
- Forces of attraction between solute particles have to be overcome for something to dissolve.
- In a mixture, one particle may fit into spaces between another type, making the total volume less than expected.
- Not every substance can be dissolved (is soluble) in a solvent.
- Dissolving is not the same as melting, but both are physical processes.
Common misconception
Forces of attraction are broken when a substance dissolves.
Forces of attraction are *overcome*. They are still acting between the particles, but weaker than before so a different particle arrangement
Keywords
Dissolve - Occurs when a substance's particles separate and spread throughout the particles of a solvent resulting in it no longer being seen.
Insoluble - If a substance does not dissolve in a particular solvent, it is described as insoluble.
Melting - Melting occurs when a substance in the solid state is heated and its particles move into the arrangement of a substance in the liquid state.
Force of attraction - A force of attraction is a pulling force that keeps things, such as particles, close together.
Suspension - A mixture of an insoluble solid and liquid in which the solid particles are dispersed in the liquid and settle upon the mixture standing.