Osmotic Pressure Dialysis Tubing

Summary

This educational video demonstrates the concept of osmosis using dialysis tubing, a semi-permeable membrane. The experiment involves placing molasses inside the tubing and submerging it in water. After two hours, the molasses in the tubing with water becomes less viscous, indicating that water molecules have passed through the membrane, diluting the molasses. This change is attributed to osmotic pressure, showcasing the principle that small molecules can pass through a semi-permeable barrier while larger ones cannot.

Takeaways

• 🧪 Dialysis tubing is a semi-permeable membrane used to demonstrate osmosis.
• 🌀 Large molecules like molasses cannot pass through the small pores of the tubing.
• 💧 Small molecules, such as water, can pass through the membrane.
• 🔬 The experiment compares the osmotic pressure inside and outside the tubing.
• 📏 Two samples are prepared: one with molasses inside the tubing and one without.
• 🎚️ The control sample remains unchanged, showing no effect of osmosis.
• ⏱️ The experiment is observed over a period of 2 hours to observe changes.
• 📈 A significant change in volume is observed in the sample with molasses.
• 📉 The viscosity of the molasses inside the tubing decreases, indicating dilution.
• 🔍 The water molecules move through the tubing, driven by osmotic pressure, diluting the molasses.

Q & A

What is dialysis tubing?

Dialysis tubing is a semi-permeable membrane that allows small molecules to pass through while preventing the passage of larger molecules.

How does the size of molecules affect their ability to pass through dialysis tubing?

Small molecules can pass through the tiny holes in the dialysis tubing, while larger molecules cannot due to their size.

What is the purpose of using molasses in the dialysis tubing experiment?

Molasses is used to demonstrate the concept of osmosis, as its large molecules cannot pass through the semi-permeable membrane, and to observe changes in volume and viscosity due to water molecules passing through.

What is the role of the control in the dialysis tubing experiment?

The control in the experiment is a dialysis tubing filled with molasses that is not placed in water. It serves as a comparison to the test sample to observe the effect of osmotic pressure.

How long does the experiment last before observing results?

The experiment is observed after 2 hours to see the effect of osmotic pressure on the molasses inside the dialysis tubing.

What change in volume is expected in the dialysis tubing containing molasses?

An increase in volume is expected as water molecules pass through the semi-permeable membrane into the dialysis tubing, diluting the molasses.

What is the expected change in viscosity of the molasses after the experiment?

The viscosity of the molasses is expected to decrease as it becomes diluted with water that has passed through the dialysis tubing.

What evidence supports the fact that water molecules moved through the dialysis tubing?

The change in volume and the decrease in viscosity of the molasses inside the dialysis tubing after the experiment indicate that water molecules have moved through the membrane.

What is the driving force that causes water molecules to move into the dialysis tubing?

Osmotic pressure is the driving force that causes water molecules to move through the semi-permeable membrane into the dialysis tubing, diluting the molasses.

Why does the control dialysis tubing remain unchanged?

The control dialysis tubing remains unchanged because it is not exposed to water, and thus there is no osmotic pressure acting on it to cause dilution.

Outlines

00:00

🧪 Osmosis Experiment with Dialysis Tubing

The paragraph describes an experiment using dialysis tubing to demonstrate the concept of osmosis. Dialysis tubing acts as a semi-permeable membrane, allowing small molecules to pass through while blocking larger ones. In the experiment, molasses is placed inside the tubing to simulate a cell. One piece of tubing serves as a control, while the other is submerged in water. After two hours, it is observed that the molasses in the water-filled tubing has become less viscous, indicating that water molecules have passed through the membrane, diluting the molasses. This change is attributed to osmotic pressure, which is the driving force for the movement of water molecules into the tubing. The control tubing shows no change, providing evidence that the semi-permeable membrane selectively allows certain molecules to pass through.

Keywords

💡Dialysis Tubing

Dialysis tubing is a semi-permeable membrane used in the field of chemistry and biology to separate substances based on their size. In the context of the video, it acts as a model for a cell membrane, allowing smaller molecules to pass through while retaining larger ones. The script describes using dialysis tubing to demonstrate the concept of osmosis by placing molasses inside and observing the effects of osmotic pressure.

💡Semi-permeable

Semi-permeable refers to a property of a membrane that allows certain substances to pass through while blocking others. This is crucial in the video as it explains how dialysis tubing functions, permitting water molecules to pass while keeping larger molasses molecules inside. The semi-permeable nature of the tubing is key to the experiment demonstrating osmotic pressure.

💡Molecules

Molecules are the smallest particles of a substance that retains its chemical properties. In the video, the size of molecules determines their ability to pass through the dialysis tubing. The script mentions that large molecules like molasses cannot pass through the tubing, while smaller molecules, like water, can.

💡Osmosis

Osmosis is the movement of solvent molecules, typically water, across a semi-permeable membrane from an area of lower solute concentration to an area of higher solute concentration. The video uses an experiment with dialysis tubing and molasses to illustrate osmosis, showing how water molecules move to equalize the concentration on both sides of the membrane.

💡Osmotic Pressure

Osmotic pressure is the pressure that needs to be applied to a solution to prevent the inward flow of water across a semi-permeable membrane. In the video, osmotic pressure is the driving force that causes water to move through the dialysis tubing into the molasses, diluting it. The experiment aims to demonstrate this concept by comparing the volume and viscosity of molasses inside the tubing to a control.

💡Molasses

Molasses is a thick, viscous byproduct of sugar refining, used in the video as a solute within the dialysis tubing. Its large molecular structure prevents it from passing through the semi-permeable membrane, making it an ideal substance to demonstrate the principles of osmosis and osmotic pressure.

💡Control

A control in an experiment is a standard or baseline used to compare with the experimental group to determine the effect of the experiment. In the video, one dialysis tubing filled with molasses serves as a control to compare against another tubing placed in water, allowing the observer to measure the impact of osmotic pressure.

💡Viscosity

Viscosity refers to the resistance of a fluid to flow. It is used in the video to describe the change in the molasses inside the dialysis tubing after osmosis has occurred. The script notes that the molasses in the tubing with water becomes less viscous, indicating that water has moved into the tubing and diluted the molasses.

💡Volume

Volume in the context of the video refers to the amount of space occupied by the substances inside the dialysis tubing. The script mentions observing a change in volume, which is a result of water molecules moving into the tubing, demonstrating the effect of osmotic pressure on volume change.

💡Beaker

A beaker is a container used in laboratories to mix, heat, or store chemicals. In the video, a beaker is used to hold water into which the dialysis tubing containing molasses is placed to initiate the osmosis process. The beaker serves as the external environment for the experiment.

💡Results

Results in scientific experiments refer to the observed outcomes or data collected. The video script mentions observing results after a two-hour period, indicating the expected change in the volume and viscosity of the molasses inside the dialysis tubing due to osmosis, which validates the presence and effect of osmotic pressure.

Highlights

Introduction to dialysis tubing as a semi-permeable membrane.

Explanation of how molecules of different sizes interact with the membrane.

Concept of osmotic pressure and its role in the experiment.

Use of molasses within the dialysis tubing to simulate a cell.

Tying off the dialysis tubing to contain the molasses.

Setting up a control experiment with untied dialysis tubing.

Placing the dialysis tubing in water to observe osmotic effects.

Expectation of observing changes in volume after 2 hours.

Observation of volume change as evidence of osmosis.

Comparison of viscosity in the dialysis tubing before and after the experiment.

Demonstration that water molecules have moved through the dialysis tubing.

Dilution of molasses as a result of osmotic pressure.

Control experiment remains unchanged, highlighting the effect of osmosis.

Practical application of osmotic pressure in understanding cellular processes.

Visual evidence supporting the theory of osmosis through the experiment.

Conclusion that the experiment successfully demonstrates the principles of osmosis.

Transcripts

this is dialysis tubing and a dialysis

tubing is a membrane that if we put a

compound inside like water or

molasses if the molecules are very large

they can't pass through the little tiny

holes in the membrane but if they're

very small they'll pass through that's

why it's called

semi-permeable little things will pass

through but not big things so what we're

going to do to test that osmotic

pressure inside and outside is we're

going to use this as if it were a cell

we're going to take the molasses and

pour into our dialysis tubing and then

we're going to tie it we're going to

make two like this one will'll use as

our control the second one will put in a

beaker of

Water 2 hours later let's see what our

results are you can see definite change

in the volumes and if we move this

around you can see that in this larger

volume the Molasses is not nearly as

viscous so we have plenty of evidence to

support the fact that the water

molecules move through the dialysis

tubing and it's diluted the molasses so

the osmotic pressure was the driving

force that brought the water in

and this one remained unchanged