Table of Contents
How does vinegar affect diffusion?
The vinegar can only enter the cube through its surface, so as that ratio decreases, the time it takes for diffusion to occur throughout the whole volume increases significantly. Anything that comes into a cell (such as oxygen and food) or goes out of it (such as waste) must travel across the cell membrane.
Why is agar used in diffusion experiment?
The impact of cell size on diffusion can be modelled with a simple experiment using different size cubes of agar containing a pH indicator. The agar cubes represent biological cells. The volume of the cube correlates to the cytoplasm and the surface area of each cube to the cell membrane.
What do the different sized agar cubes represent what does the vinegar represent?
The cubes represent a cell and the vinegar represents nutrients moving into the cell.
What substance was diffusing out of the agar cubes?
There is evidence that something diffused out of the agar since the clear sodium hydroxide solution into which the agar cubes were placed turned purple from the phenolphthalein diffusing out of the agar cube.
How does concentration affect the rate of diffusion?
The greater the difference in concentration, the quicker the rate of diffusion. The higher the temperature, the more kinetic energy the particles will have, so they will move and mix more quickly. The greater the surface area, the faster the rate of diffusion.
Why do agar cubes change color in vinegar?
Diffusion occurs when molecules in an area of higher concentration move to an area of lower concentration. As hydrogen ions from the vinegar move into the agar cube, the color of the cube changes, allowing you to see how far they have diffused.
Why does a larger surface area increase diffusion?
When a cell’s surface area increases, the amount of substances diffusing into the cell increases. As volume and surface area increase, the volume increases faster, so much so that the surface area available to allow substances in halves each time the cell volume doubles.
What is the relationship of the size of the cubes to diffusion?
In other words, if the cube dimensions are doubled, the time it takes for the hydrogen ions to completely diffuse in more than doubles. When you triple the size, the time to diffuse MUCH more than triples.
Which cube has the fastest rate of diffusion?
13. Circle the cube that has the faster rate of diffusion – circle both if the rates are the same: a big cube or a small cube – both dropped into the same temp / concentration of vinegar….
| Surface Area : Volume ratio | Length of side of a cube (cm) |
|---|---|
| 6 | 1 |
| 3 | 2 |
| 2 | 3 |
| 1.5 | 4 |
What substances can move into and out of cells by diffusion?
Water, carbon dioxide, and oxygen are among the few simple molecules that can cross the cell membrane by diffusion (or a type of diffusion known as osmosis ). Diffusion is one principle method of movement of substances within cells, as well as the method for essential small molecules to cross the cell membrane.
What are three things that affect the speed of diffusion?
Several factors affect the rate of diffusion of a solute including the mass of the solute, the temperature of the environment, the solvent density, and the distance traveled.
How does size of particles affect diffusion?
Mass of Particle: Heavier particles will move more slowly and so will have a slower rate of diffusion. Smaller particles on the other hand will diffuse faster because they can move faster.
What are 2 factors that affect the rate of diffusion?
Do larger cells diffuse faster?
How does vinegar diffuse on agar agar?
Diffusion occurs when molecules in an area of higher concentration move to an area of lower concentration. As hydrogen ions from the vinegar move into the agar cube, the color of the cube changes allowing you to see how far they have diffused.
How do you use cubes of agar to study diffusion?
Use cubes of agar to investigate how size impacts diffusion. All biological cells require the transport of materials across the plasma membrane into and out of the cell. By infusing cubes of agar with a pH indicator, and then soaking the treated cubes in vinegar, you can model how diffusion occurs in cells.
How many agar cubes should be placed in sodium hydroxide solution?
1cm agar cube before put in sodium hydroxide. 2cm cube before place in sodium hydroxide. 3cm cube placed in sodium hydroxide. All three agar cubes sliced in half to demonstrate diffusion after removed from sodium hydroxide. The 3cm cube.
How do you prepare agar agar?
Measure out 1.6 g of agar-agar and 200 ml water. Mix them together with a whisk or fork in a large microwave-safe bowl. Heat the solution in the microwave on high for 30 seconds. Remove to a heat-safe surface using a hot pad or oven mitts, stir, and return to the microwave for 30 seconds. Repeat this process until the mixture boils.