How can one separate gold from a mixture of zinc and gold? Also, how can one determine whether a white powder?

was zinc sulfide or sodium carbonate using a hydrochloric acid solution?How can one separate gold from a mixture of zinc and gold? Also, how can one determine whether a white powder?
If the white powder is sodium carbonate, when you react it with HCl, you will get carbon dioxide gas given off as one of the products of the reaction.. this gas is odorless.





If the white powder is Zinc Sulphide, when you react it with HCl, you will get sulphur dioxide gas given off as one of the products of the reaction, this gas smells like rotten eggs and is toxic.





As for the Zinc Gold mixture, you can use different methods of extraction.. both have different melting points.. you can melt the metal with the lower melting point and pour it off, or you can add a strong acid such as Sulphuric Acid to react with the mixture... Pure Gold will not react to the mixture, all the Zinc will react (in presence of enough acid) and become a salt that is soluble in water... then you just filter the gold out from the solutionHow can one separate gold from a mixture of zinc and gold? Also, how can one determine whether a white powder?
Well commenting on Paka the gas formed by the reaction of HCl to ZnS is not sulfure dioxide its hydrogen sulfide or H2S Report Abuse

Q1. Dissolve the material in a stong acid like Nitric or sulfuric acid. The Zinc should dissolve but the gold will not.


Q2. In reaction with hydrochloric acid both Zinc Sulfide and Sodium Carbonate will react- Na2CO3 forms an odorless colorless gas. ZnS will form hydrogen sulfide gas which stinks to high heaven. That would be my qualitiative test. Be careful doing this reaction in lab, as Hydrogen sulfide is a toxic gas that can be lethal. You lose the ability to smell it after exposure to high concentrations of it.
Apply heat gold will melt faster.