$(a)$ An ore on heating in air gives sulphur dioxide gas. Name the method in each metallurgical step that will be required to extract this metal from its ore.
$(b)$ State which of the following reactions will take place or not,giving a suitable reason for each.
$Zn(s) + CuSO_4(aq) \rightarrow ZnSO_4(aq) + Cu(s)$
$Fe(s) + ZnSO_4(aq) \rightarrow FeSO_4(aq) + Zn(s)$

(A) Since the ore releases $SO_2$ gas upon heating in air,it is a sulphide ore.
The steps of metallurgy are as follows:
$(i)$ Concentration of ore: Usually done by the froth floatation process for sulphide ores.
$(ii)$ Roasting: The concentrated sulphide ore is heated strongly in the presence of excess air to convert it into metal oxide.
$(iii)$ Reduction: The metal oxide is reduced to the metal by heating with a reducing agent like carbon or by self-reduction.
$(b)$ $(i)$ $Zn(s) + CuSO_4(aq) \rightarrow ZnSO_4(aq) + Cu(s)$ : This reaction will take place because $Zn$ is more reactive than $Cu$ and can displace it from its salt solution.
$(ii)$ $Fe(s) + ZnSO_4(aq) \rightarrow FeSO_4(aq) + Zn(s)$ : This reaction will not take place because $Fe$ is less reactive than $Zn$ and cannot displace $Zn$ from its salt solution.