The reaction pathway shown is a series of steps involving the oxidation of ZnS (zinc sulfide) to CuSO4 (copper sulfate). Here is the reaction pathway explained step by step:

ZnS is oxidized to form SO2 (sulfur dioxide):
ZnS + O2 → ZnO + SO2

SO2 is further oxidized to form SO3 (sulfur trioxide):
2 SO2 + O2 → 2 SO3

SO3 reacts with water to form H2SO4 (sulfuric acid):
SO3 + H2O → H2SO4

H2SO4 reacts with CuO (copper oxide) to form CuSO4 (copper sulfate):
H2SO4 + CuO → CuSO4 + H2O

Overall, the reaction pathway involves the oxidation of zinc sulfide (ZnS) to ultimately form copper sulfate (CuSO4) through a series of chemical reactions involving sulfur dioxide (SO2), sulfur trioxide (SO3), and sulfuric acid (H2SO4).