Explore BrainMass

# Osmosis finding the concentration of potato cell sap

This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

I need results for the experiment of osmosis by only changing the concentration outside the potato. But using the values
volume of the total solution 20cm cubed
the potato just using a normal cork borer cutting the pieces of potato to 2 cms
for the results I need 5 results to be taken 3 times at a range of pure water to 2 molar salt solution

https://brainmass.com/biology/research-methods-and-experimental-design/osmosis-finding-concentration-potato-cell-sap-40891

#### Solution Preview

I read through your document. First, before I give you some sample data I'd like to explain the process of osmosis so that you understand what you're doing in the experiment.

Osmosis is the process by which water moves from areas where its in high concentration to where its in low concentration. Please get that point strongly in your head. Everything diffuses naturally from places where its in higher concentration to areas where its in lower concentration.

The confusion can enter when you think about the solutes that are dissolved in the water. For example, if we make up a 10% solution of glucose, what's the percent of water? Well, it would be 90%, right? Right.

What about a 5% glucose solution? Water is at 95%, right?

Now, which if we separate these two solutions from each other by a semi-permeable membrane such that the water can freely diffuse through but the glucose cannot, which way will the water diffuse? Remember, everything diffuses from areas of high concentration to areas of low concentration. Therefore, the water will diffuse from the 5% solution to the 10% solution. Do you understand that? Water will diffuse from the 5% glucose solution to the 10% glucose solution because the 5% solution is 95% water, while the 10% solution is only 90% water. Therefore, water will diffuse from where its in high concentration to where its in low concentration.

(I spent time here explaining that because your section entitled "Planning" does not seem to convey correct understanding too well at all.)

Now, let's think about the potato experiment. Potatoes can be thought of as similar to a solution of glucose. And, therefore, we can consider diffusion of water (i.e. osmosis) across the semi-permeable membranes of the potato cells. If we put potato cells in pure water, what will happen? First of all, since pure water is 100% water, water will diffuse into the potato cells, across the semi-permeable membranes in the potato (i.e. the plasma membranes). Therefore, if we weigh the potato sections afterward, what will have happened? Clearly, the weight of the potato pieces will have ...

#### Solution Summary

The expert examines osmosis finding the concentration of potato cell sap. The volume of the total solution is determined.

\$2.19