Question

how could you separate gold from a mixture of gold and zinc?

Answer 1

there are mainly two methods for separating gold from zinc.

these two have different melting points for gold melting point is 1,064⁰C and for zinc it is 419.53⁰C .so this difference in melting point helps us to separate these two from their mixture by heating to lowest boiling point that is melting temperature of zinc.

so by heating mixture at melting point of zinc that means at 419.53⁰C zinc liquifies and gold remains as solid. by filteration these two can be separated.

another best way is to treat the mixture with sulphuric acid with which zinc can form zinc sulphate which is water soluble where as gold cannot form such compound and remains unreactive. so by pouring water to the mixure which is resulted after treatment with sulphuric acid , zinc sulphate dissolves in water and gold is insoluble in water. by filteration these can be separated.