In osmosis, water moves across a membrane from an area of
a. low concentration to an area of high concentration until both solutions are isotonic
b. high concentration to an area of low concentration until both solutions are isotonic
c. low concentration to an area of high concentration until all of the water is on one side of the membrane
d. high concentration to an area of low concentration until all of the water is on one side of the membrane
b. high concentration to an area of low concentration until both solutions are isotonic
The correct answer is b. high concentration to an area of low concentration until both solutions are isotonic.
To understand why water moves in this direction during osmosis, we need to consider the concept of concentration. Concentration refers to the amount of particles or solutes dissolved in a solution. In the context of osmosis, it specifically refers to the concentration of solute particles.
During osmosis, water molecules move across a selectively permeable membrane, which allows only certain substances, such as water, to pass through. The direction of water movement is determined by the relative concentration of solute particles on either side of the membrane.
Water has a natural tendency to move from an area of lower concentration of solute particles (dilute) to an area of higher concentration of solute particles (concentrated). This movement occurs because water molecules are constantly in motion and have the ability to pass through the membrane.
So, during osmosis, water will move from an area of high concentration of solute particles (hypertonic solution) to an area of low concentration of solute particles (hypotonic solution), in order to equalize the concentration on both sides. This continues until the solutions on both sides of the membrane reach an equilibrium, where they have the same concentration of solute particles (isotonic solution).
Therefore, option b is the correct answer, as it accurately describes the movement of water during osmosis.