Diffusion & Movement Across the Membrane Lab

Objective: The main objectives are to explain the concept of diffusion and to show the process how all materials enter and leave the cell.

Observations

Activity #1:
Food Colouring in Water
Time in Minutes
Observation
1
As the blue food colouring is dropped into the water, the drop of colour is gradually diffused throughout the water.
2
The blue food colouring continues to spread, and eventually sinks to the bottom of the beaker.
3
The blue seeps to the bottom of the beaker, however still remains on the surface of the water.

Activity #2:
Diffusion of Perfume
Time in Minutes
Observation
1
The perfume is sprayed and the scent is very potent
2
The scent is not as strong, however seems to have extended its reach past the corner
3
As the scent is diffused throughout the classroom, the strength of the scent is weakened

Activity #3:
Diffusion of Sugar Cup
Time in Minutes
Observation
0
The water tastes normal
1
After the sugar cube is dropped into the water, you can see it beginning to dissolve. The taste is still normal.
2
The taste remains the same
3
The taste remains the same
4
The taste remains the same
5
The sugar cube has diffused completely in the water – the taste of the water is now getting sweeter

Activity #4
Movement of a Gas
Time in Minutes
Observation
1
Colour changes in filter process, and swirls of pink begins to appear
2
Pink colouring begins to seep through, and continues to rise
3
Pink colouring has moved to the top of the bottle.

Activity #5
Movement of Water Through a Raisin Soaked Raisin
Un-soaked Raisin
Differences
The raisin is a lot lighter in colour
It feels softer
The raisin has become more plump due to the absorption of water
The raisin is darker, and dry
It has a hard feel to it
It is more difficult to poke through it has not been soaked in water

Analysis

How do molecules move?
In the solid phase, the atoms/molecules move, but stay in the same position relative to one another. In the liquid phase, the molecules move around and change position relative to one another while remaining in contact with each other. In the gas phase, the molecules spend almost all their time alone.

What is diffusion? Explain using a description of what happened to the drop of food colouring/air freshener molecule or the taste of the water?
Diffusion is the movement of molecules from a region of high concentration to an area of low concentration. At first the food