IMAT 2022 Question 24

Could someone please help explain why this would be A? Im lost on why the answer is just A and not the others

The question asks what happens within the “first few seconds” when the membrane (permeable to water and all sugars mentioned) is added. Answer A is correct because within a few seconds, most likely, equilibrium isn’t achieved yet. Therefore, the gradient of maltose will be from a higher concentration (Side A) to a lower concentration (Side B).

Answer B is false because sucrose will move along its gradient from Side B to A.

Answer C is false because its gradient is from Side A to Side B.

Answer D is incorrect as there will be no net movement of sugars only after some time and not at the “first few seconds.”

The solution wants to achieve equilibrium by making sides A and B equal in concentration while still having the movement of water and sugars without a net movement shifting from sides A and B (only after some time and not in the first few seconds).

Answer E is wrong because the U-tube is supposed to have symmetrical measurements if you cut it in half, and the water level will remain the same, so the solution level will be the same on both sides.