Question

3fe3o4+8al=4al2o3+9fe which is getting oxidized or reduced

Answer 1

reaction is ... $3Fe_3^{+8/3}O_4+8Al^{0}\Leftrightarrow 4Al_2^{+3}O_3+9Fe^{0}$

oxidation number of Al = 0

oxidation number of Al in Al2O3 = +3

[ we know, oxidation number of O = -2

if we assume oxidation number of Al is x

then, 2x + 3(-2) = 0 => x = +3

that's why oxidation number of Al in Al2O3 is +3]

here it is clear that aluminium is getting oxidized.

again, oxidation number of Fe in Fe3O4 = +8/3

but oxidation number of Fe = 0

here it is clear that Fe3O4 is getting reduced.