Gold dissolves in cyanide solution the presence of air to form [Au(CN)_(3)] which is stable in a cons solution. Au_((s))+CN_((s))^(-)+O_(2)+H_(2)O_(2) hArr [Au(CN)_(2)]_((aq))^(-)+OH_((aq))^(-) Aquaregia a 3 : 1 mixture of conc. HC and HNO_(3) was developed by the alchemists as a means to dissolve gold. The process is actually a Redox reaction. Au_((s))+NO_(3(aq))+Cl^(-) hArr AuCl_(4(aq))^(-)+NO_(2(g)) Gold is too noble to react with HNO_(3) However gold does react with a waregia becuase the complex AuCl_(4)^(-) forms Au_((aq))^(+3)+3e^(-) to Au_((s)) E^(theta)=15V to I AuCl_(4(aq))^(-)+3e^(-) to Au_((s))+4Cl_((q))^(-)E^(0)=1V to 2 The function of HC is to provide C what is the purpose of the Cr in the above reaction select your choice from the following.

Gold dissolves in cyanide solution the presence of air to form [Au(CN)

1.	Gold dissolves in cyanide solution the presence of air to form [Au(CN)_(3)] which is stable in a cons solution. Au_((s))+CN_((s))^(-)+O_(2)+H_(2)O_(2) hArr [Au(CN)_(2)]_((aq))^(-)+OH_((aq))^(-) Aquaregia a 3 : 1 mixture of conc. HC and HNO_(3) was developed by the alchemists as a means to dissolve gold. The process is actually a Redox reaction. Au_((s))+NO_(3(aq))+Cl^(-) hArr AuCl_(4(aq))^(-)+NO_(2(g)) Gold is too noble to react with HNO_(3) However gold does react with a waregia becuase the complex AuCl_(4)^(-) forms Au_((aq))^(+3)+3e^(-) to Au_((s)) E^(theta)=15V to I AuCl_(4(aq))^(-)+3e^(-) to Au_((s))+4Cl_((q))^(-)E^(0)=1V to 2 The function of HC is to provide C what is the purpose of the Cr in the above reaction select your choice from the following.
Answer» It is an OXIDISING agent It is a reducing agent It is a complexing agent It is a catalyst Solution :`AU^(+3)+4Cl^(-) to [AuCl_(4)]` `:. Cl^(-)` can be used as a complexing agent.