Molarity is defined as the number of moles of solute per liter of solution.

• A. Moles per liter
• B. Grams per liter
• C. Moles per milliliter
• D. Percent solution

Answer: (A)

Molarity measures how much solute is in a given amount of solution, specifically the amount per liter. That means the unit is moles per liter (mol/L). The statement aligns with that definition, so the correct description is moles per liter.

Grams per liter would be a mass concentration, not molarity. Moles per milliliter would be a similar concept but not the standard way molarity is defined, since molarity uses liters as the reference volume. Percent solution expresses concentration as a percentage (by mass or by volume) rather than as moles per liter. Also, keep in mind that molarity can vary with temperature because the volume of the solution changes the measured molarity.