Calculating the Molarity of a Diluted H2SO4 Solution

When working with solutions, it's important to understand how to calculate the molarity after dilution. This article will walk you through the process of determining the molarity of a sulfuric acid (H2SO4) solution that has been diluted. We'll use a specific example to illustrate the concept and provide a step-by-step solution.

Understanding the Concept

The molarity of a solution is defined as the number of moles of solute per liter of solution. When a solution is diluted, the total number of moles of solute remains constant. The dilution formula, C1V1 C2V2, is used to find the molarity of the diluted solution.

Problem Statement

We need to calculate the molarity of a solution resulting from a dilution process. The initial conditions are as follows:

Initial concentration (M1): 0.5 M Initial volume (V1): 30 mL Final volume (V2): 500 mL

Step-by-Step Solution

The first step in solving this problem is to convert the volumes from milliliters (mL) to liters (L), as the molarity is typically expressed in units of mol/L.

Convert the volumes:

V1 30 mL 0.030 L V2 500 mL 0.500 L

Use the dilution formula:

C1V1 C2V2

Substitute the values into the equation:

0.5 M × 0.030 L C2 × 0.500 L

Calculate the left side of the equation:

0.015 C2 × 0.500

Solve for C2:

C2 0.015 / 0.500 0.030 M

Conclusion

Therefore, the molarity of the diluted solution is 0.030 M. This process can be generalized using the formula M1V1 M2V2, where M1V1 represents the initial conditions and M2V2 represents the final conditions after dilution.

Miscellaneous Solutions

There are several alternative methods to solve the same problem:

Using the concept of millimoles, which remains constant during dilution:

M1V1 M2V2

Using the formula V1S1 V2S2 (where S represents the molarity):

30 × 0.5 500 × S2
S2 0.03 M

Using the formula M2 M1V1/V2:

M2 (0.5 × 30) / 500 0.03 M

These methods all lead to the same final result, confirming the reliability of the dilution formula.

Key Concepts

The key concepts to remember when dealing with solutions and dilutions are:

Molarity (M): The number of moles of solute per liter of solution. Dilution Formula (C1V1 C2V2): A formula used to calculate the molarity of a diluted solution. Millimoles: The number of moles expressed in milliliters, which remains constant during dilution.

まとめ (Summary)

This article has provided a comprehensive guide to calculating the molarity of a diluted H2SO4 solution. By following the steps outlined here, you can accurately determine the molarity of your solution after dilution. Understanding these concepts is crucial for anyone working with solutions in chemistry or related fields.