A high school chemistry student is preparing a solution by mixing 150 mL of 0.6 M HCl with 250 mL of 0.4 M HCl. What is the molarity of the resulting solution?
["SEO-Optimized Article: How to Calculate Molarity of a Mixed HCl Solution – A High School Chemistry Example", "Understanding how to calculate the molarity of a mixed acid solution is essential for high school chemistry students. A common problem involves mixing different volumes and concentrations of hydrochloric acid (HCl). In this article, we walk through a practical example: preparing a solution by combining 150 mL of 0.6 M HCl with 250 mL of 0.4 M HCl, and determine the final molarity of the resulting mixture.", "---", "### Understanding Molarity", "Molarity (M) is defined as the number of moles of solute per liter of solution. It is calculated using the formula:", "[\n\ ext{Molarity (M)} = \frac{\ ext{moles of solute}}{\ ext{volume of solution in liters}}\n]", "When two solutions are mixed, the total moles of HCl are found by summing the moles from each component, and the total volume becomes the sum of the individual volumes. This allows students to master both mole calculations and volume addition.", "---", "### Step-by-Step Calculation of the Mixed HCl Solution", "Given:", "- Solution 1: 150 mL of 0.6 M HCl\n- Solution 2: 250 mL of 0.4 M HCl", "Step 1: Convert volumes to liters", "- 150 mL = 0.150 L\n- 250 mL = 0.250 L", "Step 2: Calculate moles of HCl in each solution", "For Solution 1:\n[\n\ ext{Moles}1 = 0.6\ \ ext{mol/L} \ imes 0.150\ \ ext{L} = 0.090\ \ ext{mol}\n]", "For Solution 2:\n[\n\ ext{Moles}_2 = 0.4\ \ ext{mol/L} \ imes 0.250\ \ ext{L} = 0.100\ \ ext{mol}\n]", "Step 3: Calculate total moles of HCl", "[\n\ ext{Total moles} = 0.090\ \ ext{mol} + 0.100\ \ ext{mol} = 0.190\ \ ext{mol}\n]", "Step 4: Calculate total volume", "[\n\ ext{Total volume} = 0.150\ \ ext{L} + 0.250\ \ ext{L} = 0.400\ \ ext{L}\n]", "Step 5: Calculate the final molarity", "[\n\ ext{Molarity}}} = \frac{0.190\ \ ext{mol}}{0.400\ \ ext{L}} = 0.475\ \ ext{M\n]", "---", "### Why This Calculation Matters for High School Chemistry Students", "This example demonstrates key principles:\n- The directly proportional relationship between moles and volume.\n- Conservation of moles during solution mixing.\n- Proper unit conversion and volume addition.\n- Real-world application in lab preparation, critical for accurate experiments.", "Mastering these calculations supports success in standardized tests, lab assessments, and future advanced chemistry topics.", "---", "### Conclusion", "Preparing a mixed HCl solution requires careful mole and volume calculations—but with the right method, it becomes both a precise science and a powerful learning opportunity. By following clear steps to compute the total moles and total volume, the final molarity of 0.475 M emerges confidently. Whether practicing for exams or conducting real lab work, understanding how to mix solutions is a fundamental skill every chemistry student must master.", "---", "Keywords: high school chemistry, molarity calculation, HCl solution, mixing solutions, stoichiometry, concentration, dilution, chemistry experiment, acid-base preparation, moles of HCl, laboratory mixing", "Meta Description:\nLearn how to calculate the molarity of a mixed HCl solution! This high school chemistry example walks through mixing 150 mL of 0.6 M HCl with 250 mL of 0.4 M HCl, resulting in a final concentration of 0.475 M. Perfect for classroom practice and lab prep.", "---", "Use this clear example to boost your understanding of molarity and solution preparation—critical tools in chemistry!"]
