Chemistry · Grade 11

Active learning ideas

Factors Affecting Solubility

Active learning helps students visualize invisible processes like dissolving, where temperature, pressure, and surface area shape outcomes. Direct observation during hands-on labs clarifies why solids behave differently from gases, making abstract concepts concrete and memorable.

• Ontario Curriculum Expectations
• HS-PS1-3

• 20–50 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Experiential Learning
• 45 min · Small Groups

Inquiry Lab: Temperature Effects

Provide hot and cold water samples. Students test solubility of salt (solid) and fizzing tablets (gas source) in each, recording mass dissolved over time. Graph results to compare trends for solids versus gases. Discuss particle movement explanations.

Compare and contrast how temperature affects the solubility of solids versus gases in a liquid.

Facilitation Tip

During the Inquiry Lab: Temperature Effects, have students record temperature changes alongside dissolution progress to connect energy with particle behavior.

What to look for

Present students with three scenarios: 1) dissolving sugar in hot vs. cold water, 2) opening a soda bottle, 3) crushing a vitamin tablet before dissolving. Ask them to write one sentence for each explaining which factor is most important and how it affects solubility or the rate of dissolving.

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Activity 02

• Experiential Learning
• 20 min · Whole Class

Demo: Pressure and Gas Solubility

Use sealed syringes with water and effervescent tablets at different plunger pressures. Students observe bubble formation and calculate relative solubility. Relate to scuba diving or soda bottling.

Explain the effect of pressure on the solubility of gases in liquids.

Facilitation Tip

For the Demo: Pressure and Gas Solubility, use a clear syringe with colored water to show gas compression and expansion visibly.

What to look for

Pose the question: 'Imagine you are a deep-sea diver. How might the changes in pressure as you ascend affect the gases dissolved in your blood, and what precautions are necessary?' Facilitate a discussion connecting pressure and gas solubility to decompression sickness.

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Activity 03

• Experiential Learning
• 30 min · Pairs

Experiment: Surface Area Race

Compare dissolving rates of whole versus crushed antacid tablets in water. Time until full dissolution and measure pH changes. Students predict and explain outcomes using surface area principles.

Design an experiment to investigate the factors affecting the rate of dissolving.

Facilitation Tip

In the Experiment: Surface Area Race, ensure equal masses of solid samples so students focus only on surface area’s impact on rate.

What to look for

Provide students with a graph showing the solubility of a solid (e.g., KNO3) as a function of temperature. Ask them to calculate the change in solubility per 10°C increase and explain why this trend is typical for most solids.

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Activity 04

• Experiential Learning
• 50 min · Small Groups

Design Challenge: Dissolving Rate

Students select a solute and design tests for temperature, stirring, or particle size effects. Present protocols, conduct trials, and share data in a class gallery walk.

Compare and contrast how temperature affects the solubility of solids versus gases in a liquid.

What to look for

Present students with three scenarios: 1) dissolving sugar in hot vs. cold water, 2) opening a soda bottle, 3) crushing a vitamin tablet before dissolving. Ask them to write one sentence for each explaining which factor is most important and how it affects solubility or the rate of dissolving.

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

A few notes on teaching this unit

Teach this topic by pairing direct instruction with structured inquiry, as research shows students grasp solubility best when they test predictions and analyze data. Avoid overgeneralizing trends, such as assuming all solids dissolve better in heat. Instead, emphasize exceptions like gases and use analogies, like comparing pressure to squeezing a sponge, to reinforce Henry’s Law.

Students should articulate how temperature, pressure, and surface area change solubility, not just describe them. They will use data from experiments to explain trends and apply concepts to real-world scenarios like carbonated drinks or dissolving medications.

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Watch Out for These Misconceptions

• During Inquiry Lab: Temperature Effects, watch for students assuming all substances dissolve better in hot water.

  Use the lab’s sugar and salt data to ask groups to plot solubility versus temperature and identify which solid follows the expected trend and which does not, then discuss exceptions like gases.

• During Demo: Pressure and Gas Solubility, watch for students thinking pressure affects solids similarly to gases.

  After the syringe demo, have students compare pressure changes on solid salt versus dissolved CO2 in water, then ask them to explain why pressure shifts equilibrium for gases but not solids.

• During Experiment: Surface Area Race, watch for students believing that breaking a solid increases the total amount that dissolves.

  Ask students to share their final dissolved masses and discuss why crushed and whole samples reach the same total, then connect this to saturation limits and equilibrium.

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Methods used in this brief

• Experiential Learning