Grade 7 Solutions and Mixtures Review Sheet

Grade 7 Solutions and Mixtures Review Sheet
Key Vocabulary Words:
Chapter 5
 Solute
 Solvent
 Dissolving
 Soluble
 Insoluble
 Distillation
 Dilute
 concentrated
Chapter 6
 Saturated Solution
 Unsaturated Solution
 Solubility
 Supersaturated Solution
 Rate of dissolving
Key Concepts: “Big Ideas”
Chapter 5: pages 120- 145 in text book
1. Materials dissolve because their particles are attracted to the solvent particles
(please refer to page 123 in your textbook for a diagramed example)
2. Water is a “universal solvent” because many materials will dissolve in water.
This can have environmental implications because clean water is becoming a
scarce resource. Many human activities pollute our water resources.
3. Using the main ideas of the particle theory, we can separate pure water from
whatever is dissolved in it through distillation (you can learn how distillation
works on page 130 of your text book)
Chapter 6: pages 146- 175 in text book
1. Only a certain amount of solute will dissolve in a certain amount of solvent (pg
148- 149).
2. We can create a supersaturated solution by changing the temperature of the
solvent to temporarily increase the amount of solvent that can dissolve (pg 150).
3. We can change the rate of dissolving by:
Increasing the temperature of the solvent (remember, water was the
solvent in the lab that we did)
 Increasing or decreasing the size of the object that is dissolving (example:
sugar crystals vs. a sugar cube
 The rate of stirring
The particle theory can explain why these variables change the rate of dissolving.
Self Test Questions
1. Give an example of one solution that you can create at home. List the
solute and the solvent in this solution.
2. Why is water considered a “universal solvent”? What environmental
implications can arise because of this?
3. Explain how distillation works using the particle theory. You can use a
diagram to help with your explanation
4. How could you tell if a solution is saturated? Supersaturated?
5. Draw a diagram to show how a substance can dissolve in water
6. Name 3 ways that we can change the rate of dissolving. Give an example
for each.