Introduction
Osmosis is the movement of water from a region of high concentration to a region of low concentration.
Osmosis takes place when a solution is separated from another solution of a different concentration via a selectively permeable membrane. In this case water moves from a more dilute (low concentration) area to a more solute (high concentration) area.
Water molecules pass across a membrane when they collide with it as shown in the diagram:
When the membranes collide the water exerts a pressure on the membrane. This is called the water potential. Pure water has a water potential of zero so there are maximum collisions taking place which reduce the do not allow any water into the membrane.
When solute is added to the water, the solute particles get in the way of the water reducing the number of collisions and making the water potential lower and therefore allowing water into the membrane. If the water potential is negative the water will move from an area of high water potential (high water concentration) to an area of low water potential (low water concentration).
Main Experiment
Aim: To investigate the effect of different solutions of varied concentration and discover if they increase or decrease the length of a cut potato chip when kept together in an uncontrolled environment.
Science Theory: Osmosis happens when a solution is separated from it's pure water form or when a selectively permeable membrane separates two solutions. It is very similar to diffusion, but only concerns water. Water moves from a hypotonic (more water, less solute) solution to a hypertonic (less water, more solute) solution when two solutions are separated. A dynamic equilibrium is reached when both solutions become equal after osmosis which is when they are both the same and swap over equally without any total movement occurring. When a dynamic equilibrium is achieved, there is no change in the size or mass of the cells.
Water molecules move across a membrane by colliding with it, in pure water, the maximum number of collisions take place, so it is certain that no water can move in. When colliding with the membrane the water exerts a pressure, this is called the water potential. Pure water has a water potential of zero. When solute is added to the water, the sugar molecules get in the way of the water and reduce the number of collisions taking place, therefore causing a lower water potential. Water then moves from an area of high water potential (high concentration of water) to an area of low water potential (low concentration of water).
Osmosis is the movement of water from a region of high concentration to a region of low concentration.
Osmosis takes place when a solution is separated from another solution of a different concentration via a selectively permeable membrane. In this case water moves from a more dilute (low concentration) area to a more solute (high concentration) area.
Water molecules pass across a membrane when they collide with it as shown in the diagram:
When the membranes collide the water exerts a pressure on the membrane. This is called the water potential. Pure water has a water potential of zero so there are maximum collisions taking place which reduce the do not allow any water into the membrane.
When solute is added to the water, the solute particles get in the way of the water reducing the number of collisions and making the water potential lower and therefore allowing water into the membrane. If the water potential is negative the water will move from an area of high water potential (high water concentration) to an area of low water potential (low water concentration).
Main Experiment
Aim: To investigate the effect of different solutions of varied concentration and discover if they increase or decrease the length of a cut potato chip when kept together in an uncontrolled environment.
Science Theory: Osmosis happens when a solution is separated from it's pure water form or when a selectively permeable membrane separates two solutions. It is very similar to diffusion, but only concerns water. Water moves from a hypotonic (more water, less solute) solution to a hypertonic (less water, more solute) solution when two solutions are separated. A dynamic equilibrium is reached when both solutions become equal after osmosis which is when they are both the same and swap over equally without any total movement occurring. When a dynamic equilibrium is achieved, there is no change in the size or mass of the cells.
Water molecules move across a membrane by colliding with it, in pure water, the maximum number of collisions take place, so it is certain that no water can move in. When colliding with the membrane the water exerts a pressure, this is called the water potential. Pure water has a water potential of zero. When solute is added to the water, the sugar molecules get in the way of the water and reduce the number of collisions taking place, therefore causing a lower water potential. Water then moves from an area of high water potential (high concentration of water) to an area of low water potential (low concentration of water).
