Solution Concentration: Merging 0.2M HCl and 75 mL of 0.6M HCl

When working with solutions in the laboratory, it is often necessary to calculate the final concentration of mixed solutions. This article will guide you through the process of determining the resultant solution of combining 0.2M HCl and 75 mL of 0.6M HCl. By breaking down the steps and explaining each one, you'll gain a deeper understanding of the principles behind solution concentration and molarity.

Understanding Concentration and Molarity

Before we dive into the calculations, it is essential to understand the concepts of concentration and molarity. Concentration generally refers to the amount of solute present in a solution. Molarity, specifically, is the concentration of a solution expressed as the number of moles of solute per liter of solution. It is denoted as [subscript]M[/subscript] (molar).

Step-by-Step Guide: Calculating Resultant Concentration

To find the resultant concentration of the solution formed when 0.2M HCl and 75 mL of 0.6M HCl are mixed, follow these steps:

Step 1: Calculate the Total Moles of HCl in 0.2M HCl Solution

The first step is to determine the total number of moles of HCl in the 0.2M HCl solution. To do this, you need to know the volume of the 0.2M HCl solution. Let's denote this volume as (V_1) liters. The formula to calculate the moles of solute in a given solution is:

moles [Molarity] × [Volume (in liters)]

So, the moles of HCl in 0.2M HCl solution is:

moles_1 0.2 M × (V_1) L

Step 2: Calculate the Total Moles of HCl in 75 mL of 0.6M HCl Solution

Next, convert the volume of the 75 mL 0.6M HCl solution to liters as the molar concentration requires the volume in liters. So, 75 mL is equivalent to 0.075 L. Using the same formula, the moles of HCl in the 0.6M HCl solution is:

moles_2 0.6 M × 0.075 L

Step 3: Add the Moles Together

Add the moles of HCl from both solutions to find the total moles of HCl in the mixed solution:

Total moles moles_1 moles_2

Step 4: Calculate the Total Volume

When mixing two solutions, simple addition of their volumes is a good approximation, but it is not always precise. The exact volume change due to mixing can be complex. However, in this case, we will use the total volume as an approximation:

Total volume (V_1) L 0.075 L

Step 5: Calculate the Resultant Molarity

Finally, calculate the molarity of the mixed solution by dividing the total number of moles by the total volume in liters:

Molarity (final) Total moles / Total volume (in liters)

For a sanity check, ensure that the final molarity is within the range of the original concentrations, which is between 0.2 M and 0.6 M. The final molarity will be closer to the concentration of the solution with the larger volume.

Conclusion

By following these steps, you can accurately determine the resultant concentration of a mixed HCl solution. This method is versatile and can be applied to various scenarios involving the mixture of different concentrations of solutions. Understanding these principles is crucial for accurate experiments and laboratory work.

Additional Resources

If you want to learn more about solution concentration, molarity, and chemical solutions, consider exploring the following resources:

Chemistry Textbooks Online Courses on Chemistry Laboratory Manuals for Chemistry

Feel free to reach out if you have any further questions or need additional assistance.