10. How Is AuCl3 Prepared?

AuCl3, also known as gold(III) chloride, can be prepared by reacting gold metal with chlorine gas or hydrochloric acid. One common method involves dissolving gold metal in aqua regia (a mixture of concentrated nitric and hydrochloric acids) to form chloroauric acid (HAuCl4), which is then treated with hydrochloric acid and an oxidizing agent such as chlorine gas or hydrogen peroxide to yield AuCl3. Another method involves reacting gold metal with dry chlorine gas at high temperatures. The resulting AuCl3 can be purified by recrystallization from a suitable solvent.