Final answer:
The osmolality of the interior of the cell is equal to that of the 0.5 molar glucose solution outside it, since the cell's volume does not change when it is placed in this solution.
Step-by-step explanation:
The question concerns the concept of osmosis and osmolality in the context of a plant cell's interaction with its environment. When a plant cell is placed in a solution and its volume does not change, this indicates that the solution is isotonic with the interior of the cell. The fact that glucose cannot pass through the cell membrane indicates that the solution outside the cell must have the same osmolality as the inside of the cell since there is no net flow of water in either direction.
The osmolality of the cell’s interior can be concluded to be equal to the 0.5 molar glucose solution outside the cell. This is because osmosis would lead to a net flow of water into or out of the cell if there were a difference in osmolality, causing the cell to either swell or shrink, which does not occur in this scenario.