Aqua regia releases nascent………….

The mixture of nitric acid (HNO₃) and hydrochloric acid (HCl) is known as Aqua Regia, which literally means “Royal Water.” It is so named because it can dissolve noble metals like gold and platinum, which are otherwise highly resistant to dissolution in ordinary acids.

When nitric acid and hydrochloric acid are combined, they react to form nitrosyl chloride (NOCl), water (H₂O), and nascent chlorine (Cl).

The exceptional reactivity of Aqua Regia is attributed to the presence of nascent chlorine, which is extremely reactive due to its unpaired electron in a high-energy orbital. This allows it to attack noble metals. For example, it reacts with gold to form a soluble complex: tetrachloroaurate (III) [AuCl₄]⁻.

Thus, Aqua Regia’s ability to dissolve noble metals comes from the generation of nascent chlorine, making the mixture far more powerful than either nitric acid or hydrochloric acid alone.