Grade 5 · Science · Unit 3 of 6
Solutions & Mixtures
Dissolving and separating mixtures
What your child practises
Solutions versus mechanical mixtures, solutes and solvents, what affects dissolving, and ways to separate mixtures (filtering, evaporation, magnets, chromatography).
NWT Curriculum learning standard: Solutions and solubility; mixtures and separation techniques
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
How can you get pure water back from salt water? Put the steps in order.
- ❄️The vapour touches a cold surface and condenses
- 🔥Heat the salt water
- ♨️Water evaporates and the salt stays behind
- 💧Drops of pure water drip into a clean cup
Heat the salt water → Water evaporates and the salt stays behind → The vapour touches a cold surface and condenses → Drops of pure water drip into a clean cup
Hint: Heat makes the water evaporate and leave the salt behind. Then the water vapour cools, condenses and drips into a clean container.
Question 2
What pattern does this table show?
Sugar that dissolves in 100 mL of water (about) Water temperature Sugar dissolved 20 °C 200 g 40 °C 240 g 60 °C 290 g 80 °C 360 g - temperature doesn't change how much dissolves
- the warmer the water, the less sugar dissolves
- the warmer the water, the more sugar dissolves
- sugar dissolves only in cold water
the warmer the water, the more sugar dissolves
Hint: Read down both columns. As the temperature goes up, the grams of sugar go up too, so solubility increases.
Question 3
Which tool would separate iron filings from sand?
🧲- a magnet
- a filter
- a thermometer
- a measuring cup
a magnet
Hint: Iron is attracted to magnets. Sand is not.
Question 4
Soluble or insoluble in water? Tap an item, then tap its basket.
Sort into: 💧 soluble · 🚫 insoluble
- 🍬sugar
- 🍯honey
- 🍚uncooked rice
- 🧂table salt
- 🪨pebbles
- 🏖️sand
💧 soluble: sugar, honey, table salt · 🚫 insoluble: uncooked rice, pebbles, sand
Hint: A soluble substance dissolves and seems to disappear in water. An insoluble one stays visible, sinks or floats.
Question 5
A sieve separates the parts of a mixture by their…
- size
- temperature
- colour
- magnetism
size
Hint: Small pieces fall through the holes in a sieve; bigger pieces stay on top.
Question 6
A dot of black marker on wet paper spreads out into several colours. What is this separation method called?
🖊️- chromatography
- sieving
- filtration
- evaporation
chromatography
Hint: In chromatography, water carries each ink colour a different distance up the paper, separating the mixture.