In gold mining , cyanide solutions are often used to dissolve AuBr from ore samples. In the presence of cyanide ions, CN-, gold forms a soluble complex according to the following reaction: Au+ + 2CN- ↔ Au(CN)2-. The formation of this complex causes the AuBr in the ore to dissolve. The Au(CN)2- complex has a Kform = 2.0x1013 and the Ksp of AuBr is 5.0x10-13.
Would this be the correct net reaction?
AuBr-->Au + Br
Au + 2CN-↔ Au(CN)2
AuBr+2CN---Au(CN)2+Br