Diffusion

• Chemistry
• Secondary Education
• Age 12,13

IGCSE Chemistry 0620

Topic 2 States of Matter

11 September 2023

Describe how you feel right now 

using an emoji.

😒🙁😐🙂😃

• explain changes of state in terms of kinetic particle theory, including the interpretation of heating and cooling curves  
• describe and explain diffusion in terms of kinetic particle theory  
• describe and explain the effect of relative molecular mass on the rate of diffusion of gases  

I intend to:

11 September 2023, Monday

IGCSE Chemistry 0620

Topic 2 States of Matter

11 September 2023

• 🜛 Present the cooling curve made (two groups only).
• 🜛 Processing and feedback

Retrieval Activity

11 September 2023, Monday

11 September 2023, Monday

Interpretation

• Sloped lines: temperature of the state of matter is increasing.
• Horizontal lines: change of state (no change of temperature)
• This is a HEATING CURVE.

Processing

11 September 2023, Monday

Interpretation

• Sloped lines: decrease in temperature
• Horizontal lines: change of state (no change of temperature)
• This is a COOLING CURVE.

Processing

11 September 2023, Monday

Interpretation

• What is happening at B and D?
• What states are A and C?
• Explain using the KPT.

Processing

IGCSE Chemistry 0620

Topic 2 States of Matter

11 September 2023

• What happens to the colourless hot water when you put a tea bag in it?

A question that matters! 

11 September 2023, Monday

Key Concept

11 September 2023, Monday

• Diffusion—  a process by which different gases or different liquids mix and is due to the random motion of their particles

IGCSE Chemistry 0620

Topic 2a States of Matter

06 September 2023

Investigation 01

KMnO₄ in a petri dish of water

11 September 2023, Monday

• Discuss how and why diffusion happened in this case

Processing

11 September 2023, Monday

	OBSERVATIONS after 5 minutes
Diffusing particles
Movement of diffusing particles
The concentration of diffusing particles after 5 minutes
Why is energy NOT required?

Investigation 02

 Diffusion of tea

11 September 2023, Monday

• Discuss how the diffusion of tea happened 

Processing

11 September 2023, Monday

	OBSERVATIONS after 5 minutes
Diagram showing diffusion every one minute.
Description of the water (colour change)

Compare/contrast observations with the KMnO₄ and tea diffusion

• Rate of diffusion
• Movement of diffusing particles

Processing

11 September 2023, Monday

Investigation 03

 Diffusion of gases

11 September 2023, Monday

DO: Note down significant points related to diffusion in your notebook.

🜛 SHARE: Give at least three points you noted 

Processing

11 September 2023, Monday

• faster diffusion in gases than in liquids
• at the same temperature = different gases do not diffuse at the same rate (speed) WHY?
• Lighter (lower relative mass) gas particles = travel faster and farther

Processing

11 September 2023, Monday

• faster diffusion in gases than in liquids
• at the same temperature = different gases do not diffuse at the same rate (speed) WHY?
• Lighter (lower relative mass) gas particles = travel faster and farther

Processing

11 September 2023, Monday

• NH3 molecules have less mass than the HCl molecule, so diffuse faster, hence the product (a white smoke of NH4Cl) forms closer to the end where the HCl is.

IGCSE Chemistry 0620

Topic 2 States of Matter

11 September 2023

Classwork 5 

Diffusion

06 September 2023, Monday

IGCSE Chemistry 0620

Topic 2 States of Matter

11 September 2023

Topic Assessment 1

States of Matter

11 September 2023, Monday

Self-Assessment for Learning

11 September 2023, Monday

T O  D O:

• Identify two ideas you do not understand quite well in our sessions.
• Ask someone who can explain and write the explanations in your notebook.
• Verify your learning from a classmate by sharing it with the teacher.

Week 06 Reflection 1:

Why does a car tire explode 

when the temperature increases?