Page 129 - Knowledge Organiser Yr7 24-25

Knowledge Base: Science 7.5 Mixtures Year 7
1. Dissolving and Solutions
1.1
Is dissolving a physical or chemical change?
A physical change.
2. Concentration
2.1
What is meant by the concentration of a solution?
The mass of solute dissolved in 1000cm3 of solvent.
2.2
What are the units for concentration?
g/cm3
2.3
What is the difference between a concentrated and dilute solution?
In a concentrated solution, there are more particles of solute per 1000cm3 than in a dilute solution.
2.4
Draw a particle diagram to show a concentrated solution and a dilute solution:
1.2 What is a solute?
1.3 What is a solvent?
1.4 What is a solution?
The substance that dissolves to make the solution.
The substance dissolving the solute.
A mixture of a solute that has been dissolved by a solvent.
1.5
What happens to particles during dissolving?
• Particles of the solvent collide with particles of the solute, surrounding them.
• Particles of the solute gradually move away from each other.
• Until the particles are evenly spread through the solvent.
1.6
What happens to the mass of solvent and solute during dissolving?
The mass of the solvent and solute before and after dissolving stays constant.
1.7
What happens to the volume of the solvent during dissolving and why?
The volume of the solvent remains constant. Because the solute particles fit into gaps between the solvent particles.
1.8
What is meant by a soluble substance?
A substance which is able to dissolve.
1.9
What is meant by an insoluble substance?
A substance which is unable to dissolve.
1.10
Draw a particle diagram to show dissolving:
3. Solubility and Saturation
3.1
What is solubility a measure of?
How much solute can dissolve in a volume of solvent at a specific temperature.
3.2
What effect will increasing temperature have on the solubility of a solute?
The solubility will normally increase.
3.3
What is meant by a saturated solution?
A solution in which no more solute can dissolve.
3.4
What causes a solution to become saturated?
When all the spaces between the solvent particles are occupied.
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