Osmosis

Osmosis

Introduction

Osmosis is the passage of water from a region of high water

concentration through a semi-permeable membrane to a region of low

water concentration.

The aim of the investigation is to find the variables that affect the

rate of osmosis and how they affect the rate of reaction.

The variables that affect the rate of reaction of osmosis are,

· The surface area of the object,

· The concentration of the solution,

· Temperature of the experiment

Surface area

If the surface area of the object is larger then more molecules can

pass through the semi-permeable membrane.

This will ultimately increase the rate of reaction.

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Small surface area Large surface area

Concentration

If the concentration of the solution is high then it will contain more

molecules and so the rate of reaction will be shorter.

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Low concentration High concentration

Temperature of the experiment

Generally the higher the temperature, the less time it takes for a

reaction. But with living cells there is a point at which the cell

will be denatured therefore the rate of reaction will be altered, as

the cells are no longer functioning.

Hypothesis

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Osmosis is defined as the movement of water or any other solution's

molecules from a region of highly concentrated solution to a region of

less concentrated solution. This movement must take place across a

partially permeable membrane such as a cell wall, which lets smaller

molecules such as water through but does not allow bigger molecules to

pass through. The molecules will continue to diffuse until the area in

which the molecules are found reaches a state of equilibrium, meaning

that the molecules are randomly distributed throughout an object, with

no area having a higher or lower concentration than any other.

To make this investigation fair, the conditions will be as follows:

Changed variable

Constants