Unit 1.2 - diffusion

Question 1

Define concentration

Answer 1

The measure of the number of particles in a given volume

Question 2

Define diffusion

Answer 2

The net movement of particles from an area of high concentration to an area of low concentration, until the concentration becomes even/reaches equilibrium. Down the concentration gradient, no energy required.

Question 3

Which 3 factors affect the rate of diffusion?

Answer 3

1. State of matter - gases have a higher rate of diffusion because they are more spread out and move faster than particles in a liquid
2. Temperature - the higher the temperature, the more kinetic energy particles have, which means they can move faster which increases the rate of diffusion
3. Molecular mass - large molecules do not move as far as smaller molecules, because they carry more mass and require more kinetic energy to move over the same distance. This means that they diffuse slower

Question 4

Define concentration gradient

Answer 4

The difference in concentration between two spaces

Question 5

Explain why it could take longer than 1 minute for the white ring to form, when the Hcl and Ammonia particles travel more than 1m/s and the tube is 0.9 m long

Answer 5

There are air particles present in the tube in which the 2 compounds are diffusing in, which the particles of said compounds will collide with, as well as the walls of the tube due to their random rapid motion. This will slow down the rate of diffusion, as the particles aren’t traveling in a straight line.