Aqua regia is an acidic, corrosive and oxidative mixture consisting of ________ volume/volumes of concentrated hydrochloric acid and one volume of concentrated nitric acid, often used to dissolve gold and platinum.

Three

The correct answer is option 2. Three.

Aqua regia is an acidic, corrosive, and oxidative mixture consisting of Three volumes.

Aqua regia is typically composed of three volumes of concentrated hydrochloric acid and one volume of concentrated nitric acid. This mixture is highly reactive and is often used to dissolve noble metals such as gold and platinum due to its ability to form complex ions with these metals, allowing for their dissolution.