Foundations of Matter and Chemical Change · 5th Year

Active learning ideas

Solutions: Dissolving Materials

Active learning works well for dissolving materials because students need to observe firsthand how particles behave when they dissolve. Watching sugar vanish in water or testing salt solubility helps them move past abstract ideas to concrete evidence they can trust and explain.

• NCCA Curriculum Specifications
• NCCA: Primary - Materials - Solutions

• 25–50 min
• Pairs → Whole Class
• 4 activities

Activity 01

• 35 min · Pairs

Dissolving Speed Trials: Temperature Effects

Pairs fill three beakers with equal solute amounts in cold, room-temperature, and hot water. They stir each at the same rate and time until fully dissolved. Groups graph results and predict outcomes for new trials.

What happens when sugar disappears in water?

Facilitation Tip

During Dissolving Speed Trials, set clear time intervals and have students record observations every 30 seconds to build a reliable data set.

What to look for

Provide students with three scenarios: 1) Sand mixed with water, 2) Salt dissolved in water, 3) Milk added to water. Ask them to identify which scenario represents a solution and explain why, using the terms solute and solvent.

Activity 02

• Stations Rotation
• 45 min · Small Groups

Stations Rotation: Solubility Tests

Set up stations with water and materials like sugar, salt, sand, oil. Small groups test solubility, record observations in tables, then rotate. Conclude with class share-out on patterns.

Can everything dissolve in water?

Facilitation Tip

For Station Rotation, rotate groups every 8 minutes to keep engagement high and ensure all stations are visited.

What to look for

Present students with a list of substances (e.g., oil, sugar, sand, copper sulfate). Ask them to predict which are soluble in water and which are insoluble. Then, have them briefly explain their reasoning based on prior knowledge or observations.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 03

• 25 min · Individual

Particle Size Challenge: Whole vs. Crushed

Individuals crush half their solute sample and test dissolving times against whole pieces in equal water volumes. They measure and compare, noting the effect of surface area.

How can we make something dissolve faster?

Facilitation Tip

In Particle Size Challenge, pre-measure materials so students focus on the crushing process and fair comparisons.

What to look for

Pose the question: 'Imagine you have a glass of iced tea and a glass of hot tea, both with sugar added. Which one will dissolve faster and why?' Facilitate a class discussion where students explain the role of temperature in dissolving rates.

Activity 04

• 50 min · Small Groups

Saturation Point Hunt

Small groups add solute to water incrementally until no more dissolves, then filter and evaporate to recover undissolved amount. They calculate saturation from mass changes.

What happens when sugar disappears in water?

Facilitation Tip

During Saturation Point Hunt, provide test tubes and spoons so students can measure additions precisely without spills.

What to look for

Provide students with three scenarios: 1) Sand mixed with water, 2) Salt dissolved in water, 3) Milk added to water. Ask them to identify which scenario represents a solution and explain why, using the terms solute and solvent.

A few notes on teaching this unit

Teach dissolving by starting with familiar examples before moving to controlled experiments. Avoid abstract models early, as they can confuse students who haven’t yet observed the phenomenon. Use guided inquiry to help students connect their observations to particle theory, reinforcing that dissolving is reversible and doesn’t destroy matter.

By the end of these activities, students should confidently describe dissolving as a process of particle separation, not disappearance. They’ll use terms like solute, solvent, and solubility accurately and connect everyday examples to scientific concepts.

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Watch Out for These Misconceptions

• During Dissolving Speed Trials, watch for students who claim the solute is gone because they can’t see it.

  Have students taste or evaporate the solution to prove the solute remains intact, using the trial cups as evidence.

• During Station Rotation, watch for students who assume all powders dissolve in water.

  Guide students to test materials like sand and oil, then discuss why only some form solutions based on their observations at each station.

• During Particle Size Challenge, watch for students who believe stirring is the only way to speed dissolving.

  Use the crushed vs. whole particle data to show how surface area affects rate, then discuss other factors like temperature uncovered in Dissolving Speed Trials.

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Methods used in this brief

• Stations Rotation