To study osmosis, a student placed a thin potato slice in a salt solution. The slice became soft and shriveled. Then, he placed the shriveled slice in water. The slice regained its original shape. Based on the observations, which of these statements is correct? Responses A The slice regained its shape because salt moved into the potato.The slice regained its shape because salt moved into the potato. B The potato slice shriveled because water moved from the salt solution into the slice.The potato slice shriveled because water moved from the salt solution into the slice. C The potato slice shriveled because water moved out of the slice into the salt solution.The potato slice shriveled because water moved out of the slice into the salt solution. D The slice regained its shape because the concentration of salt inside and outside the slice became equal.
C The potato slice shriveled because water moved out of the slice into the salt solution.
The correct statement is D. The slice regained its shape because the concentration of salt inside and outside the slice became equal.
Explanation:
Osmosis is the movement of water molecules across a semi-permeable membrane from an area of low solute concentration to an area of high solute concentration. In this case, when the potato slice was placed in the salt solution, the salt concentration outside the slice was higher than inside the slice. As a result, water from inside the potato moved out to the salt solution, causing the potato slice to shrivel and become soft.
When the shriveled potato slice was placed in water, the opposite process occurred. The water concentration outside the slice was higher than inside the slice. Therefore, water molecules moved from the surrounding water into the potato slice, equalizing the salt concentration and causing the slice to regain its original shape.
The correct statement is C: The potato slice shriveled because water moved out of the slice into the salt solution.
To understand why this is the correct statement, let's break down the process of osmosis and apply it to the given scenario. Osmosis is the movement of water molecules across a selectively permeable membrane (in this case, the cell membrane of the potato slice) from an area of higher water concentration to an area of lower water concentration, in an attempt to equalize the concentration of solutes on both sides of the membrane.
When the thin potato slice was placed in a salt solution, which is a hypertonic solution (a solution with a higher solute concentration compared to the potato cells), water molecules from inside the potato cells moved out of the cells and into the salt solution. This movement of water out of the cells caused the potato slice to lose water, resulting in the slice becoming soft and shriveled. Hence, the correct statement is that the potato slice shriveled because water moved out of the slice into the salt solution.
When the shriveled potato slice was then placed in water, which is a hypotonic solution (a solution with a lower solute concentration compared to the potato cells), water molecules from the surrounding water moved into the potato cells. This movement of water into the cells caused the potato slice to regain its original shape as it reabsorbed water.
The statement D, which suggests that the concentration of salt inside and outside the slice became equal, is incorrect because osmosis does not involve the movement of solutes (salt in this case) across the membrane. Osmosis only involves the movement of water molecules.