(E) Diffusion Flashcards
What is diffusion?
The movement of substances from a region of high to low concentration
Where does diffusion happen?
Diffusion can happen through mainly gases and liquids
Why can diffusion happen in liquids and gases?
This is because the particles in liquid and gases can move randomly
What is the arrangement of particles in liquid and gases?
Random movement of particles
In liquids they are close together and move around each other
In gases they are far apart and move quickly in any direction
Why does diffusion not happen in solids?
This is because the particles are at a fixed position vibrating
What is dynamic equilibrium and what does it have to do with the concentration gradient?
During diffusion, after the molecules become uniformly distributed, dynamic equilibrium exists.
Particles in an area of high concentration gradient will diffuse into an area of low concentration gradient, down a concentration gradient
What is the equation for moles?
moles = volume x concentration (mol = dm^3 x (mol/dm^3)
What are the factors that affect diffusion?
- Concentration gradient
- Shape and size of molecules
- Temperature
- Diffusion distance
- Surface area – surface area to volume ratio
- Energy of molecules
- Membranes and barriers
What is the concentration gradient?
When the concentration of particles is higher in one area than another
How does the concentration gradient affect diffusion?
The steeper the concentration gradient and the faster the molecules of a substance will diffuse because the molecules have more space to move to
How does the shape and size of the molecules affect diffusion?
Larger molecules move more slowly then smaller ones so the rate of diffusion decreases
How does the temperature affect diffusion?
A higher temperature increases the energy molecules have and so they move faster which increases the rate of diffusion
What is the diffusion distance?
The distance that a particle can diffuse in the area it is in
How does the diffusion distance affect diffusion?
If the diffusion distance is small, diffusion happens faster because the particles do not have as far to travel
How does the surface area affect diffusion?
The larger the surface area the higher the number of particles that will be able to move in a given time so the faster the rate
