Chemistry · Year 11

Active learning ideas

Factors Affecting Solubility

Active learning helps Year 11 students grasp solubility factors because hands-on experiments make abstract concepts like kinetic energy and Henry’s Law visible. Students see temperature and pressure effects with their own eyes, which builds durable understanding beyond memorizing graphs or rules.

• ACARA Content Descriptions
• ACSCH061
• ACSCH062

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

Activity 01

• Stations Rotation
• 50 min · Small Groups

Temperature Series: Solid Solubility

Prepare water baths at 20°C, 40°C, and 60°C. Students add excess salt to equal volumes of water, stir for 5 minutes, then filter and evaporate to find dissolved mass. Groups plot solubility vs. temperature and compare solids like sugar and salt.

Explain how temperature affects the solubility of solids and gases.

Facilitation Tip

During Temperature Series: Solid Solubility, have students record mass dissolved at each temperature on a shared class chart to build a collective solubility curve.

What to look for

Provide students with a solubility curve for potassium nitrate. Ask them to answer: 1. What is the solubility of KNO3 at 40°C? 2. If you dissolve 70g of KNO3 in 100g of water at 30°C, is the solution saturated, unsaturated, or supersaturated? Explain why.

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

Activity 02

• Stations Rotation
• 30 min · Pairs

Pressure Test: Gas Solubility

Use sealed syringes with water and CO2 tablets at different plunger pressures. Students measure volume of dissolved gas by displacement after shaking. Record data and discuss Henry's Law application.

Analyze the effect of pressure on the solubility of gases.

Facilitation Tip

During Pressure Test: Gas Solubility, demonstrate the gas collection setup before students begin to prevent leaks and ensure consistent pressure readings.

What to look for

Present students with three scenarios: a) heating a solid in water, b) cooling a gas in water, c) increasing pressure on a gas in water. Ask them to predict whether solubility will increase or decrease in each case and briefly justify their answer based on the principles discussed.

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

Activity 03

• Stations Rotation
• 35 min · Small Groups

Surface Area Race: Dissolution Rate

Provide whole and crushed antacid tablets. Drop into identical water volumes, time full dissolution with and without stirring. Groups tabulate results and graph rate differences.

Predict how stirring and surface area influence the rate of dissolution.

Facilitation Tip

During Surface Area Race: Dissolution Rate, provide identical solute masses but different surface areas to make the rate difference obvious.

What to look for

Facilitate a class discussion using the prompt: 'Imagine you are a chemist designing a process to remove dissolved gases from wastewater. What factors would you manipulate, and why, to achieve the lowest possible gas concentration?'

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

Activity 04

• Stations Rotation
• 25 min · Pairs

Stirring Speed Comparison

Dissolve identical sugar amounts in water with slow, medium, and fast stirring. Use stopwatches to record time to clear solution. Analyze how agitation affects particle collision frequency.

Explain how temperature affects the solubility of solids and gases.

Facilitation Tip

During Stirring Speed Comparison, use timers at each stirring speed so students quantify how stirring affects rate without altering final solubility.

What to look for

Provide students with a solubility curve for potassium nitrate. Ask them to answer: 1. What is the solubility of KNO3 at 40°C? 2. If you dissolve 70g of KNO3 in 100g of water at 30°C, is the solution saturated, unsaturated, or supersaturated? Explain why.

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

A few notes on teaching this unit

Teach this topic by first establishing the difference between rate and equilibrium solubility. Use analogies students know, like sugar dissolving faster in hot tea but not more sugar dissolving at higher altitude. Avoid rushing through Henry’s Law; let students discover gas behavior through their own pressure tests to build ownership of the concept. Research suggests students retain this better when they test predictions rather than just observe demonstrations.

Successful learning looks like students explaining why temperature increases solid solubility but decreases gas solubility, citing data from their experiments. They should also distinguish between factors that affect rate (stirring, surface area) and those that change equilibrium solubility (temperature, pressure for gases).

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Watch Out for These Misconceptions

• During Temperature Series: Solid Solubility, watch for students assuming all solutes behave like table salt, ignoring gas solubility trends.

  After the activity, ask groups to present their findings on both solids and gases, highlighting the opposite trends and plotting the data on a shared graph to address the misconception directly.

• During Pressure Test: Gas Solubility, watch for students applying solid solubility rules to gases.

  Ask students to predict what happens to a solid’s solubility when pressure increases, then test their hypothesis with a solid sample to show no change, reinforcing the distinction.

• During Surface Area Race: Dissolution Rate, watch for students believing that crushing a solute increases the final amount dissolved.

  Have students measure and compare the final mass dissolved for both crushed and whole samples, then discuss why the rate differs but the saturation point remains the same.

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Methods used in this brief

• Stations Rotation