Investigating the Effect of Concentration of a Certain Salt Solution on the Amount Tissue of Potato Slices
Aim:
The aim of the experiment is to investigate the effect of
concentration of a certain salt solution on the amount tissue of
potato slices.
Osmosis is the movement of a solvent (e.g. water) through a semi
permeable membrane, from a solution that has a lower concentration of
solutes (e.g. salt) to one that has a higher concentration of solutes.
In osmosis, the membrane does not allow the solute to pass through,
but does allow the solvent to pass through. The rate in which osmosis
occurs depends on the temperature of the solution, the concentration
of the solute, and the electrical charge of the solute. Another factor
is the difference between the pressures that both sides of the
solutions exert onto the membrane. Osmosis stops when the two
solutions are equal in concentration.
Prediction:
For this investigation I think that the lower the concentration of the
salt solution the larger the mass of the potato will be at the end.
This is because the water molecules pass from a high concentration
(solution) to a low concentration (potato). As a result the potato in
lower molar concentrations will gain a larger mass than in higher
molar solutions.
To create a fair test variables of the experiment will have to be kept
the same whilst only one variable is changed. I have chosen to vary
the morality of the salt solution. If the solution volume, duration of
experiment, temperature, solution or scales are not kept constant it
would not be a fair test. For example if one of the potato slices was
longer than another then the surface area of the potato would be
larger and there would be more space for osmosis to occur. Doing all
the tests at one temperature will control the temperature, I will try
to work at room temperature and will leave all of the tubes in the
same place so that they are all experiencing the same conditions.