No net mass change indicates equal water potential

Steps:

• Identify the point on the graph where the mass ratio is 1 (no change in mass).
• This occurs when water potential of potato cells equals that of the sucrose solution.
• Locate the concentration corresponding to this point.
• The graph shows this at 0.3 mol dm⁻³.

Why B is correct:

• At equal water potentials, osmosis causes no net water movement, so mass remains unchanged (water potential equilibrium).

Why the others are wrong:

• A: Lower concentration means higher solution water potential, causing water influx and mass increase.
• C: Higher concentration means lower solution water potential, causing water efflux and mass decrease.
• D: Even higher concentration amplifies water loss, leading to greater mass decrease.

Final answer: B