Question

Also known as "royal water" or "king's water", it is a mixture of nitric acid and hydrochloric acid, optimally in a molar ratio of 1:3. Usually it is in orange and yellow colour.

Answer 1

royal water" or "king's water") is a mixture of nitric acid and hydrochloric acid, optimally in a molar ratio of 1:3. Aqua regia is a yellow-orange (sometimes red) fuming liquid, so named by alchemists because it can dissolve the noble metals gold and platinum, though not all metals.