A cell has a salt concentration of 0.2 %. If it is placed into a solution with a salt concentration of 0.1 %.
a) What change will occur to the salt concentration inside the cell?
b)What change will occur to the water concentration inside the cell?
c)What condition will eventually result from the net movement of water and salt?
To answer the questions, we need to understand the process of osmosis, which is the movement of solvent molecules (in this case, water) across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.
a) What change will occur to the salt concentration inside the cell?
In this scenario, the salt concentration in the cell is higher (0.2%) compared to the solution it is placed in (0.1%). According to osmosis, water molecules will move from an area of lower solute concentration (0.1% solution) to an area of higher solute concentration (0.2% salt concentration inside the cell). As a result, the water will leave the cell, causing an increase in the salt concentration inside the cell.
b) What change will occur to the water concentration inside the cell?
As water moves out of the cell due to the osmotic process described earlier, the water concentration inside the cell will decrease. The movement of water across the membrane will continue until the salt concentration inside and outside the cell reaches an equilibrium.
c) What condition will eventually result from the net movement of water and salt?
The net movement of water from a region of lower solute concentration (0.1% solution) to a region of higher solute concentration (0.2% salt concentration inside the cell) will lead to an equilibrium. Eventually, the water and salt concentration inside the cell and in the surrounding solution will become equal. This condition is called isotonic, where the solute concentrations are the same and there is no net movement of water.