Osmosis Experiment

Osmosis Experiment

Aim of the Experiment

The aim of this experiment is to examine the concept of osmosis. It attempts to monitor the behaviour of sucrose solution submerged in water to detect any changes in the quantity. The other solution, which is used as a neutral tester for the experiment, is distilled water.

Introduction

The phenomenon of osmosis was first discovered by the German botanist Wilhelm Pfeffer 100 years ago. Osmosis is the transfer of solvent through the membrane due to osmotic pressure (Doris, Carl, Robert, & John, 1997, pp 16). Osmosis is the penetration of the solvent (for example, water) from a solution where it is in lower concentration to a solution where it is higher in concentration through a semi permeable membrane. It is the transport of material from one solution to another through the membrane (Warren, 1992, pp 230 - 232). The membranes are permeable for certain substances and thus, are termed as semi permeable membranes. Water molecules pass through the semi permeable membrane from the solution of lower concentration: this is called a hypotonic solution, and the highest concentration, hypertonic solution. When the flow of water equal to the two concentrations, the solutions are called isotonic (Doris, Carl, Robert, & John, 1997, pp 16).

Materials and Methods

Materials used in the Experiment

The experiment for determining and examining osmosis utilized some common and simple materials. These materials are listed below:

Sucrose Solution (1M),

Visking Tubing,

Crystallizing Dishes,

Distilled Water, and

Syringes

Step by Step Methods for the Experiment

The experiment for examining the process of osmosis was conducted as per the following procedure:

The length of visking tubing was rinsed with water inside and out under a tap in order to make it more pliable. A knot was tied at one end and the tube was filled with tap water. Any possible leakages were checked before hand to ensure that the experiment results are purely as per the osmosis process. The tube was then emptied squeezing out excess water.

15 cm3 sucrose solution was put into the visking tubing using a syringe.

The open end of the visking tubing was carefully tied ensuring that no room is left for possible expansions. Possibilities of leakages was also checked.

The tube was then blotted and weighed.

An identical control set-up was prepared using distilled water in the visking tube. It was also blotted and weighed.

Each tube was then laid in a crystallising dish leaving the ends protruding.

Sufficient distilled water was added to the dishes until the filled regions of tubing was completely submerged in the water.

After 15 minutes, both the visking tubes were carefully removed, blotted and reweighed. They were then returned to their respective crystallising dishes.

The step (H) was repeated thrice.

The results were recorded in a table (presented in Results section).

Results

The mass of sucrose solution and the mass of distilled water after every 15 minutes is presented in the table below:

TIME(Minutes)

MASS OF TEST TUBING (g)(Sucrose Solution)

MASS OF CONTROL TUBING (g)(Distilled Water)

0 Mins

15.90 g

17.93 g

15 Mins

17.59 g

17.79 g

30 Mins

19.04 g

17.79 g

45 Mins

20.38 g

17.71 g

Discussion of Results

The visking plays the role of a ...