Electrometallurgy is used for

Identify the correct statements for the following reaction sequence:
$Ag + NaCN (0.5\%) + H_2O + O_2 \to \text{Soluble complex} \xrightarrow{Zn} B (\text{complex}) + Ag$

In the $Hall-Heroult$ process,aluminium is formed at the cathode. The cathode is made out of

Identify $A$ and $B$ respectively in the following reactions:
$4 Au_{(s)} + 8 CN^{-}_{(aq)} + 2 H_2O_{(aq)} + O_{2(g)} \longrightarrow 4 A_{(aq)} + 4 OH^{-}_{(aq)}$
$2 A_{(aq)} + Zn_{(s)} \longrightarrow B_{(aq)} + 2 Au_{(s)}$

The materials mixed with the ore before it is subjected to smelting in the extraction of iron are:

The Ellingham diagram of a certain metal $M$ is represented in the figure. The points $A$ and $B$ respectively correspond to: