Aqua regia

Aqua Regia (Akwuh Reejuh) is a mixture of It was named so because it can dissolve some noble metals, particularly gold and platinum. Aqua regia does not dissolve titanium, iridium, ruthenium, rhenium, tantalum, niobium, hafnium, osmium, or rhodium, and has a limited effect on silver.

Uses

• Can dissolve noble metals such as gold and platinum

Character

Reactions

• Pt + 4 HNO₃ + 6 HCl → H₂PtCl₆ + 4 NO₂ + 4 H₂O (hexachloroplatinic acid)
• Au + 3 HNO₃ + 4 HCl → HAuCl₄ + 3 NO₂ + 3 H₂O (Chloroauric acid)

Production

• Combine 1 ubv of azeotropic (68%) nitric acid with 3 ubv of azeotropic (22%) hydrochloric acid.

Storage

• Sealable glass containers

Disposal

• Combine with Sodium hydroxide producing a mixture of sodium nitrate and sodium chloride.

Hazards

• Extremely corrosive

See Also

• Nitric acid
• Hydrochloric acid