Two acid solutions are prepared: Solution A contains 0.50 mol of HCl dissolved in 1.0 L of water, and Solution B contains 0.25 mol of HCl dissolved in 0.5 L of water. Which solution is more concentrated?

• A. Both solutions have the same concentration
• B. Solution B
• C. Cannot be determined from the information given
• D. Solution A

Answer: (B)

Verified step by step guidance

1. Identify the concentration unit to compare the two solutions. The most common concentration unit for solutions is molarity (M), which is defined as moles of solute per liter of solution.
2. Calculate the molarity of Solution A using the formula \(M = \frac{\text{moles of solute}}{\text{volume of solution in liters}}\). For Solution A, this is \(M_A = \frac{0.50\ \text{mol}}{1.0\ \text{L}}\).
3. Calculate the molarity of Solution B using the same formula. For Solution B, this is \(M_B = \frac{0.25\ \text{mol}}{0.5\ \text{L}}\).
4. Compare the molarities \(M_A\) and \(M_B\) to determine which solution is more concentrated. The solution with the higher molarity is more concentrated.
5. Based on the comparison, select the correct answer: either Solution A, Solution B, or if they are equal, then both have the same concentration.