This lesson contains 27 slides, with interactive quiz and text slides.
Lesson duration is: 55 min
Items in this lesson
Lesson 1 - What is IGCSE Chemistry?
4
9
Lesson 8 - Diffusion
Slide 1 - Slide
Today, I'm going to...
know about diffusion in liquids and gases,
be able to describe what happens during diffusion using the KPT, and
understand why diffusion happens at different rates.
Lesson 8 - Diffusion
Slide 2 - Slide
I can define diffusion.
I can describe the kinetic energy and movement of particles during diffusion.
I can describe the effect of higher relative molecular mass on the rate of diffusion of gases.
I can describe the effect of lower relative molecular mass on the rate of diffusion of gases.
I am successful if...
Slide 3 - Slide
Slide 4 - Slide
Prepare your blue or black pen.
Open your Workbook on page 3.
Complete Focus 2 and Practice 3.
You only have 3 minutes to complete your responses.
Workbook Exercise
timer
3:00
Slide 5 - Slide
ANSWERS
Slide 6 - Slide
ANSWERS
B
C
A
D
Slide 7 - Slide
ANSWERS
B
C
A
D
impossible
Slide 8 - Slide
Slide 9 - Slide
Structures of solids, liquids and gases
KPT
SOLID
LIQUID
GAS
Kinetic energy of particles
Low energy
Medium energy
High energy
Motion of particles
Vibrating at a fixed position
Moving slide past each other
Moving freely and quickly
Arrangement of particles
Regular, in rows
Irregular
Irregular
Separation of particles
Close together, (all) touching
Close together, (some) touching
Far apart
Forces between particles
van der Waals forces
cohesive forces
NO force between particles
Slide 10 - Slide
Kinetic Particle Theory
Kinetic energy
Motion
Arrangement
Forces
Separation
Slide 11 - Slide
Slide 12 - Slide
Slide 13 - Slide
Method
Investigating diffusion in liquids
Add 20 cm3 of room temperature water to Petri dish A.
Add 20 cm3 of warm water to Petri dish B.
Using a spoon, simultaneously add a small amount of potassium permanganate to the middle of Petri dishes A and B.
In which water does the solid diffuse faster?
Slide 14 - Slide
phet.colorado.edu
Slide 15 - Link
Method
Investigating diffusion of bromine in air
Add two drops of liquid bromine to a test tube and put a rubber cork to seal it.
Start the stopwatch immediately after closing.
Observe.
Stop the stopwatch once the gas occupies the whole test tube.
How long do two drops of bromine liquid diffuse in a test tube?
Slide 16 - Slide
Slide 17 - Slide
Key Question:
Which fume has a greater rate of diffusion: hydrogen chloride or ammonia?
Background information:
When ammonia and hydrogen chloride gases meet in a sealed tube, they react to form a white smoke ring of ammonium chloride. The mass of ammonia gas is 17.0 g/mol, and the mass of hydrogen chloride gas is 36.5 g/mol.
Hypothesis:
___________________________________________
SDA 1.2 (Practical): Investigating the rate of diffusion
Slide 18 - Slide
Risks:
Corrosive [C] chemical: Hydrochloric acid
Corrosive [C] chemical: Aqueous ammonia
Safety precautions:
Wear a laboratory coat throughout the experiment.
Tie your long hair.
Avoid smelling the chemicals directly. WAFT, if required.
Wear safety glasses throughout the experiment.
Wear safety gloves.
Slide 19 - Slide
Method
Put the soaked cotton wool with hydrochloric acid in the bottom of the test tube using forceps.
Put the soaked cotton wool with aqueous ammonia near the mouth of the test tube.
Seal the test tube with a rubber stopper.
Observe.
Record your observations on the datasheet.
Slide 20 - Slide
Slide 21 - Slide
Slide 22 - Slide
I can define diffusion.
I can describe the kinetic energy and movement of particles during diffusion.
I can describe the effect of higher relative molecular mass on the rate of diffusion of gases.
I can describe the effect of lower relative molecular mass on the rate of diffusion of gases.
I am successful if...
Slide 23 - Slide
Self-check
Open your notebook.
Look for this.
Read.
Reflect.
Complete.
Slide 24 - Slide
Name something you did not know before this lesson,