Which of the following expressions correctly defines molarity (M)?

• A. moles of solute divided by kilograms of solvent
• B. moles of solute divided by liters of solution
• C. grams of solute divided by milliliters of solution
• D. grams of solute divided by liters of solution

Answer: (B)

Verified step by step guidance

1. Understand that molarity (M) is a measure of concentration that relates the amount of solute to the volume of the solution.
2. Recall the definition of molarity: it is the number of moles of solute dissolved in one liter of solution.
3. Express this definition mathematically as \(M = \frac{\text{moles of solute}}{\text{liters of solution}}\).
4. Note that molarity is not based on the mass of solvent or solute alone, but specifically on the volume of the entire solution.
5. Compare the given options to this definition and identify the expression that matches \(M = \frac{\text{moles of solute}}{\text{liters of solution}}\).