Chemistry Help!! Can somebody please help me!!?

Gold is an extremely unreactive metal, gold does react, however, with aqua regia (a mixture of concentrated nitric acid, HNO3(aq) and hydrochloric acis, HCL(aq)). The complex ion AuCl4, as well as N2 and H2O are formed. this reaction is always carried out with aqua regia in excess. why would a chemist not have the gold in excess?