5th grade · Science · Unit 1 of 9
Solutions & Mixtures
Dissolving and separating mixtures
What your child practices
Solutions versus mechanical mixtures, solutes and solvents, what affects dissolving, and ways to separate mixtures (filtering, evaporation, magnets, chromatography).
Maine Learning Results learning standard: 5-PS1-3; 5-PS1-4 · identifying materials by their properties and testing whether mixing makes new substances
How we explain it
Children can open this short lesson before they practice.
- In a solution, one substance dissolves into another, like salt in water.
- A filter separates things that don't dissolve, like sand from water.
- Dissolved salt is too tiny for a filter, so heat the water to evaporate it. The salt stays behind.
- Cool the vapor and it condenses back into pure water.
Example: How could you get the salt back out of salt water? Salt is dissolved, so a filter won't catch it. Heat the water until it evaporates. The salt is left behind. Answer: evaporate the water
Solutions & Mixtures in Maine
In the Maine Learning Results, this is unit 1 of 9 in 5th grade Science, before Solid, Liquid, Gas.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Source: Maine Department of Education
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
Kenji has a dry mix of iron filings, sand and salt. Put his separation steps in order.
- ☕Pour it through a filter to catch the sand
- ☀️Let the water evaporate to leave the salt
- 🧲Run a magnet through the dry mix to pull out the iron
- 🥄Add water and stir until the salt dissolves
Run a magnet through the dry mix to pull out the iron → Add water and stir until the salt dissolves → Pour it through a filter to catch the sand → Let the water evaporate to leave the salt
Hint: Use the magnet while the mix is still dry. Then dissolve the salt, filter out the sand, and evaporate the water to get the salt back.
Question 2
What does solubility mean?
- how much of a substance can dissolve in a solvent
- how heavy a substance is
- how well a substance floats
- how fast a substance melts
how much of a substance can dissolve in a solvent
Hint: Solubility is the amount of solute that can dissolve in a certain amount of solvent at a certain temperature.
Question 3
Which substance will dissolve in water?
- pebbles
- sand
- sugar
- cooking oil
sugar
Hint: Sugar is soluble: it dissolves and spreads evenly through the water.
Question 4
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 - the warmer the water, the more sugar dissolves
- sugar dissolves only in cold water
- temperature doesn't change how much dissolves
- the warmer the water, the less sugar dissolves
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 5
Which tool would best separate sand from water?
- a filter, like a coffee filter
- a ruler
- a magnet
- a thermometer
a filter, like a coffee filter
Hint: A filter lets water through but catches the bigger, undissolved sand grains.
Question 6
A dot of black marker on wet paper spreads out into several colors. What is this separation method called?
🖊️- chromatography
- filtration
- evaporation
- sieving
chromatography
Hint: In chromatography, water carries each ink color a different distance up the paper, separating the mixture.