How to Prepare a 5 Molar H2SO4 Solution Safely and Efficiently

Preparing a 5 Molar (5M) H2SO4 solution is a common procedure in many laboratory settings. This guide will walk you through the necessary steps to safely and accurately create this solution. The instructions provided are designed to ensure safety, accuracy, and reliability.

Materials Needed

Concentrated sulfuric acid (typically around 98% w/v) Distilled water A balance A graduated cylinder or volumetric flask A beaker Protective equipment: gloves, goggles, and a lab coat

Steps for Preparation

1. Calculate the Amount of Concentrated H2SO4 Needed

To create 100 mL of a 5 M H2SO4 solution, you will need 5 grams of H2SO4. The density of concentrated sulfuric acid is approximately 1.84 g/mL. Therefore, the volume of concentrated sulfuric acid needed can be calculated as follows:

Volume mass / density 5 g / 1.84 g/mL ≈ 2.72 mL

2. Measure the Concentrated H2SO4

Carefully measure approximately 2.72 mL of concentrated sulfuric acid using a pipette or graduated cylinder. This step is critical as it ensures the precision of your solution.

3. Add Water to the Beaker

In a beaker, add about 50 mL of distilled water. It is important to always add acid to water, not the other way around, to prevent exothermic reactions that can cause splattering and potential safety hazards.

4. Add the Concentrated H2SO4

Slowly and carefully add the measured concentrated sulfuric acid to the water while continuously stirring. This ensures uniform mixing and helps to dissipate any heat generated during the mixing process.

5. Adjust the Volume

After the acid is fully mixed with the water, transfer the solution to a 100 mL volumetric flask and add distilled water until the total volume reaches 100 mL. This step ensures that the final concentration is accurate.

6. Mix the Solution

Thoroughly mix the solution by inverting the volumetric flask or gently stirring. The solution should be well-mixed to ensure uniform concentration.

7. Label the Solution

Clearly label the container with the concentration (5 M H2SO4) and the date of preparation. This information is crucial for future reference and to ensure traceability.

Safety Precautions

Always wear appropriate personal protective equipment (PPE), such as gloves, goggles, and a lab coat. Work in a well-ventilated area or under a fume hood to minimize exposure to fumes and protect your respiratory system. Handle sulfuric acid with care as it is a highly corrosive substance. Ensure that all storage and disposal procedures adhere to safety guidelines.

This method will yield a 5 M H2SO4 solution suitable for various applications, including experiments, titrations, and other laboratory activities.