Saved Bookmarks
| 1. |
In the reaction of gold with aquaregia, oxidation state of Nitrogen changes from |
|
Answer» Solution :Gold ores are leached with sodium cyanide solution in presence of air. Due to oxidation gold DISSOLVES in sodium cyanide FORMING COMPLEX. `8NaCN + 4Au + 2H_(2)O + O_(2) rarr 4Na[Au(CN)_(2)] + 4NaOH` The metal is recovered by displacement METHOD by adding zinc. `2Na[Au(CN)_(2)] + Zn rarr Na_(2)[Zn(CN)_(2)] + 2Au`. |
|