The oxidising and reducing agents respectively for the cyanide extraction of silver from argentite ore are

During the electrolytic reduction of alumina,two auxiliary electrolytes $X$ and $Y$ are added to increase the electrical conductance and lower the melting point of the mixture. $X$ and $Y$ are:

In Hall’s process,the main reagent is mixed with

The metal oxide which cannot be reduced to metal by carbon is

On heating a mixture of $Cu_2O$ and $Cu_2S$,the product obtained is:

Which of the following statements is/are correct based on the provided Ellingham diagram?