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Grade 8 · Science · Unit 1 of 16

Mixtures, Solutions & WHMIS

Dissolving, concentration and safe handling

What your child practises

Safety symbols on hazardous products, telling pure substances, mechanical mixtures and solutions apart, what changes how fast and how much a solid dissolves, and measuring concentration in grams per 100 mL.

Nunavut Curriculum approved guide: Nunavut adaptation of Alberta Science 7–9 (2003), Unit A: Mix and Flow of Matter · WHMIS symbols, pure substances, mixtures and solutions, solubility and concentration, using the particle model

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    In salt water, which part is the solute?

    • the air
    • the salt
    • the cup
    • the water

  2. Question 2

    Which is a solution?

    • sugar completely dissolved in water
    • oil floating on vinegar
    • sand stirred into water
    • pebbles in a bucket

  3. Question 3

    For most solids, what usually happens to solubility when the water is heated?

    • Nothing dissolves.
    • The solute turns into a gas.
    • Less solute can dissolve.
    • More solute can dissolve.

  4. Question 4

    Which change speeds up how fast sugar dissolves in water?

    • using a bigger cup
    • using bigger lumps of sugar
    • stirring
    • cooling the water

  5. Question 5

    A student crushes a sugar cube before adding it to water. What does this change?

    • The sugar can never dissolve.
    • The sugar changes into salt.
    • The sugar dissolves faster because there is more surface touching the water.
    • The water gets heavier.

  6. Question 6

    A solution has 24 g of sugar dissolved in 200 mL of solution. What is the concentration, in g per 100 mL?

    answer boxg/100 mL

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