Which of the following best describes the relationship between the amount of solute and the molarity of a solution, assuming the volume remains constant?

• A. Molarity remains unchanged as the amount of solute increases.
• B. Molarity is independent of the amount of solute.
• C. Molarity increases as the amount of solute increases.
• D. Molarity decreases as the amount of solute increases.

Answer: (C)

Verified step by step guidance

1. Recall the definition of molarity (M), which is the concentration of a solution expressed as the number of moles of solute per liter of solution. The formula is given by: \(M = \frac{\text{moles of solute}}{\text{liters of solution}}\).
2. Since the problem states that the volume of the solution remains constant, the denominator in the molarity expression does not change.
3. Consider what happens when the amount of solute (moles) increases while the volume stays the same: the numerator in the molarity formula increases.
4. Because molarity is directly proportional to the number of moles of solute when volume is constant, increasing the amount of solute will increase the molarity.
5. Therefore, the correct relationship is that molarity increases as the amount of solute increases, assuming constant volume.