Answer:
4Al203 + 9Fe -> 3Fe3O4 + 8Al
Amount of Al on reactant side: 8
Amount of Al on product side: 8
Amount of O on reactant side: 12
Amount of O on product side: 12
Amount of Fe on reactant side: 9
Amount of Fe on product side: 9
HCl is considered as polar molecule and that is incorrect answer, The choices provided are A) HCl , B) CH₄ , C) H₂O, D) NH₃
And the correct answer is : B) CH₄
In case of H₂O and NH₃ the high difference in electronegativity between nitrogen or oxygen and hydrogen make the bonds acquire partial charges and become polar while in case of CH₄ the difference in electronegativity between carbon and hydrogen is only 0.4 so it considered as non-polar bond
also carbon connected from all directions with Hydrogens
Answer: Oxidation is defined as the reaction in which there is loss of electrons. It is accompanied by increase in oxidation number.

Zinc in solid state has oxidation number of zero and on losing electrons changes to
with oxidation number of +2.
Reduction is defined as the reaction in which there is gain of electrons. It is accompanied by decrease in oxidation number.

Hydrogen ions with +1 oxidation state gains electrons and converts to molecular hydrogen with oxidation state of zero.
In the given redox reaction, both oxidation and reduction takes place. They go hand in hand.

Zinc converts to
and gets oxidized.
gains electron and convert to
.