Four beakers contain aqueous solutions: Beaker A has 0.5 mol NaCl in 1.0 L, Beaker B has 1.0 mol NaCl in 2.0 L, Beaker C has 0.25 mol NaCl in 0.5 L, and Beaker D has 2.0 mol NaCl in 4.0 L. Which beaker contains the solution with the highest concentration?

• A. Beaker B
• B. Beaker C
• C. Beaker D
• D. Beaker A

Answer: (B)

Verified step by step guidance

1. Identify that the concentration of each solution is given by its molarity, which is defined as the number of moles of solute divided by the volume of the solution in liters. The formula is: \(M = \frac{\text{moles of solute}}{\text{volume of solution in liters}}\).
2. Calculate the molarity for Beaker A using the given data: moles = 0.5 mol, volume = 1.0 L. So, \(M_A = \frac{0.5}{1.0}\).
3. Calculate the molarity for Beaker B: moles = 1.0 mol, volume = 2.0 L. So, \(M_B = \frac{1.0}{2.0}\).
4. Calculate the molarity for Beaker C: moles = 0.25 mol, volume = 0.5 L. So, \(M_C = \frac{0.25}{0.5}\).
5. Calculate the molarity for Beaker D: moles = 2.0 mol, volume = 4.0 L. So, \(M_D = \frac{2.0}{4.0}\). Compare all the molarities calculated to determine which beaker has the highest concentration.