Investigating the Movement of Osmosis through a Selectively Permeable Membrane

Investigating the Movement of Osmosis through a Selectively Permeable Membrane

My aim for this experiment is to see the percentage increase decrease

and results of potato tissue's mass difference, when placed in

different concentrations of sugar solutions. This investigation would

expect to have 3 different variables, Independent, which you can

change, the thing that I will be changing in this investigation for

the factors affecting osmosis, is the concentrations of the solution

that changes the mass and investigate osmosis with potato tissues. The

different sugar concentrations will be changed to see the result of

the potatoes when placed in sugar solutions placed in different

molarities (strengths of solution). Dependent, the things that I'll be

measuring in this experiment on osmosis is the mass change of the

potatoes placed in different molarities of sugar solutions. I will

record the masses in grams by using a balance and fixed variables, the

things that I have chosen to keep the same in each individual

experiment to keep it a fair test is to keep the same sizes of each

potato, the same by using the same cork borer and will try to keep the

weight similar. I will be keeping the same amount of solution placed

in the test tubes for each different experiment, which I will measure

using a measuring cylinder. I will also be keeping the same potato

through out the whole experiment to as using a different one might

give me irregular result as some might have more water in it then

others affecting the weight and change in mass. These variables all

help me to plan and explain the experiment to measure the mass

increase or decrease.

Introduction

What is Osmosis?

Osmosis is movement of water through a selectively permeable membrane,

from where there is a higher water concentration (or water potential)

to where the water concentration is lower. If you put a piece of

potato into pure water, the water concentration is obviously higher

outside the potato. Therefore water moves into the potato by osmosis.