The role of depressants in 'Froth Flotation method' is to

Given below are two statements :

Statement I : According to Ellingham diagram, any metal oxide with higher $$\Delta$$G$$^\circ$$ is more stable than the one with lower $$\Delta$$G$$^\circ$$.

Statement II : The metal involved in the formation of oxide placed lower in the Ellingham diagram can reduce the oxide of a metal placed higher in the diagram.

In the light of the above statements, choose the most appropriate answer from the options given below :

Given below are two statements.

Statement I : During electrolytic refining, blister copper deposits precious metals.

Statement II : In the process of obtaining pure copper by electrolysis method, copper blister is used to make the anode.

In the light of the above statements, choose the correct from the options given below.

Leaching of gold with dilute aqueous solution of NaCN in presence of oxygen gives complex [A], which on reaction with zinc forms the elemental gold and another complex [B]. [A] and [B], respectively are :