How does the addition of a carbohydrate modular affect osmolality?

• A. Will decrease osmolality
• B. Will increase osmolality
• C. Will not change osmolality
• D. Effect depends on amount

Answer: (B)

Adding a carbohydrate modular increases osmolality because osmolality reflects the number of osmotically active particles in a kilogram of solvent. Each molecule of carbohydrate that enters the solution adds to the particle count, so more carbohydrate means more solute particles and a higher osmolality. The exact amount you add will determine how much the osmolality rises, but the direction is always upward with addition. This is why increasing carbohydrate content tends to raise osmolality, whereas removing solute or adding only solvent would decrease or leave osmolality unchanged, and saying it depends on amount is less precise than stating the consistent direction of change with addition.