In the extraction process of copper,the product obtained after carrying out the reactions
$(i) 2 Cu_2S + 3 O_2 \rightarrow 2 Cu_2O + 2 SO_2$
$(ii) 2 Cu_2O + Cu_2S \rightarrow 6 Cu + SO_2$ is called

The maximum temperature $1550$ $^oC$ is obtained in the ......... region of the blast furnace used in the extraction of iron.

Which of the following elements is present as the impurity to the maximum extent in the pig iron?

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A:$ In an Ellingham diagram,the oxidation of carbon to carbon monoxide shows a negative slope with respect to temperature.
Reason $R:$ $CO$ tends to get decomposed at higher temperature.
In the light of the above statements,choose the correct answer from the options given below:

$I$. $FeCr_2O_4 + NaOH + \text{air} \rightarrow Na_2CrO_4 + Fe_2O_3$
$II$. $Na_2CrO_4 + H_2SO_4 \rightarrow Na_2Cr_2O_7$
$Na_2CrO_4$ and $Fe_2O_3$ are separated by:

Limestone is used as a flux in the extraction of