Given below are two statements related to Ellingham diagram:
Statement-$I$ : Ellingham diagrams can be constructed for formation of oxides,sulfides and halides of metals.
Statement-$II$ : It consists of plots of $\Delta_f H^0$ vs $T$ for formation of oxides of elements.
In the light of the above statements,choose the most appropriate answer from the options given below:

Consider the following metallurgical processes:
$I$. Heating impure metal with $CO$ and distilling the resulting volatile carbonyl (b.p. $43 \ ^oC$) and finally decomposition at $150 \ ^oC - 200 \ ^oC$ to get the pure metal.
$II$. Heating the sulphide ore in air until a part is converted to oxide and then further heating in the absence of air to let the oxide react with unchanged metal sulphide.
$III$. Electrolysis of the molten electrolyte containing approximately equal amounts of the metal chloride and $NaCl$ to obtain the metal.
The processes used for obtaining magnesium,nickel and copper are respectively:

Identify the reaction,which is not related to the extraction of copper.

In the reaction,$P_2O_5 + 3CaO \to Ca_3(PO_4)_2$,$P_2O_5$ acts as......

Consider the following statements:
$(a)$ When the lead-silver alloy is rich in silver,lead is removed by the cupellation process.
$(b)$ Froth flotation can be applied for non-sulphide ores also using a suitable activator.
$(c)$ $PbSO_4 + H_2SO_4$ electrolyte is used for the refining of $Pb$ by electrolysis.
$(d)$ Any metal will not reduce the oxide of other metals which lie above it in the Ellingham diagram.
Using $'T'$ for true and $'F'$ for false statements in the given sequence,select the correct set of code.

Identify the products of the reaction: $4FeCr_2O_4 + 8Na_2CO_3 + 7O_2 \rightarrow ?$