How to Safely Prepare and Use Aqua Regia Solution- A Comprehensive Guide

How to Prepare Aqua Regia Solution

Aqua regia, also known as king’s water, is a highly corrosive mixture of hydrochloric acid and nitric acid. It is used primarily in analytical chemistry to dissolve gold and other noble metals. Preparing aqua regia requires careful handling and precise measurements to ensure safety and effectiveness. In this article, we will guide you through the steps to prepare aqua regia solution.

Materials Needed:

Before starting the preparation process, gather the following materials:

– 1 liter of concentrated hydrochloric acid (HCl)
– 1 liter of concentrated nitric acid (HNO3)
– Glass beaker or flask
– Glass stirring rod
– Safety goggles
– Lab gloves
– Lab coat
– Fume hood

Step 1: Safety Precautions

Aqua regia is a highly toxic and corrosive mixture. Always wear safety goggles, lab gloves, and a lab coat when handling the chemicals. Ensure that you are working in a well-ventilated area, such as a fume hood, to avoid inhaling harmful fumes.

Step 2: Measuring the Chemicals

Pour 500 milliliters of concentrated hydrochloric acid into a glass beaker or flask. Then, carefully add 500 milliliters of concentrated nitric acid to the beaker. Use a glass stirring rod to mix the chemicals thoroughly. It is essential to add the hydrochloric acid first, as it is more reactive and can cause an exothermic reaction if added to the nitric acid.

Step 3: Mixing the Chemicals

Continue to stir the mixture for several minutes to ensure that the hydrochloric acid and nitric acid are thoroughly combined. The resulting solution should have a bright orange or red color, indicating the formation of aqua regia.

Step 4: Storage

Once the aqua regia solution is prepared, transfer it to a labeled, glass bottle with a tight-fitting lid. Store the bottle in a cool, dry place away from direct sunlight. It is crucial to keep the solution away from incompatible materials, such as metals, as it can cause reactions that may lead to explosions or fires.

Step 5: Usage and Disposal

When using aqua regia, always follow proper safety procedures and guidelines. Ensure that you are working in a well-ventilated area and that you have the necessary protective equipment. After using aqua regia, dispose of the solution according to local regulations and guidelines. Never pour the solution down the drain or into the environment.

In conclusion, preparing aqua regia solution requires careful handling and precise measurements. By following these steps and taking necessary safety precautions, you can successfully prepare and use aqua regia for various analytical applications.