Aqua Regia Mixing Calculator

Historical Background

Aqua regia, meaning "royal water" in Latin, is a highly corrosive mixture of nitric acid (HNO₃) and hydrochloric acid (HCl) commonly used to dissolve noble metals such as gold and platinum. Originating in medieval alchemy, it became valuable in modern times for its ability to refine precious metals and dissolve difficult metals that are resistant to other acids.

Calculation Formula

The calculator determines the volume of nitric acid needed based on a given volume of hydrochloric acid and the desired ratio. Aqua regia is traditionally mixed at a 3:1 HCl to HNO₃ ratio.

The calculations are as follows: \[ \text{Nitric Acid Volume} = \frac{\text{Hydrochloric Acid Volume}}{\text{Mixing Ratio (3:1)}} \] \[ \text{Total Volume of Aqua Regia} = \text{Hydrochloric Acid Volume} + \text{Nitric Acid Volume} \]

Example Calculation

If you start with 300 ml of hydrochloric acid and use the 3:1 ratio:

• Nitric Acid Volume = \( \frac{300}{3} = 100 \, \text{ml} \)
• Total Volume = \( 300 + 100 = 400 \, \text{ml} \)

Importance and Usage Scenarios

Aqua regia plays an essential role in laboratories for refining metals and conducting analytical chemistry. Due to its strength, aqua regia should be prepared only when needed and handled with extreme caution in well-ventilated areas with protective equipment. Its ability to dissolve gold, platinum, and other noble metals makes it invaluable in fields such as metallurgy, precious metal recovery, and industrial chemistry.

Common FAQs

1. What is the proper ratio for mixing aqua regia?

   • The classic ratio is 3:1 hydrochloric acid to nitric acid by volume.

2. Why is aqua regia so reactive?

   • Aqua regia's reactivity is due to the combination of nitric acid, which provides powerful oxidizing agents, and hydrochloric acid, which supplies chloride ions that aid in dissolving metal compounds.

3. How long can I store aqua regia?

   • Aqua regia should be used immediately after preparation, as it loses potency over time and emits toxic fumes.

4. What safety precautions should be taken?

   • Use in a fume hood, wear gloves and eye protection, and avoid storing due to its volatile and toxic nature.