Answer:
The redox reactions are: (a) 3Fe₂O₃(s) + CO(g) ⟶ 2Fe₃O₄(s) + CO₂(g)
b) Fe₃O₄(s) + CO(g) ⟶ 3FeO(s) + CO₂(g)
c) FeO(s) + CO(g) ⟶ Fe(l) + CO₂(g)
d) C(s) + O₂(g) ⟶ CO₂(g)
e) C(s) + CO₂(g) ⟶ 2CO(g)
Explanation:
Redox reaction is a type of chemical reaction that involves the <u>simultaneous transfer of electrons and change in the oxidation state.</u>
The chemical species that accepts electrons and gets reduced is called an oxidizing agent. Whereas, chemical species that loses electrons and gets oxidized is called a reducing agent.
(a) 3Fe₂O₃(s) + CO(g) ⟶ 2Fe₃O₄(s) + CO₂(g)
In this reaction, Fe accepts electrons and gets reduced from +3 oxidation state in Fe₂O₃ to +8/3 (+2.66) oxidation state in Fe₃O₄. Whereas, C loses electrons and gets oxidized from +2 oxidation state in CO to +4 oxidation state in CO₂.
<em><u>Therefore, it is a redox reaction.</u></em>
b) Fe₃O₄(s) + CO(g) ⟶ 3FeO(s) + CO₂(g)
In this reaction, Fe accepts electrons and gets reduced from +8/3 (+2.66) oxidation state in Fe₃O₄ to +2 oxidation state in FeO. Whereas, C loses electrons and gets oxidized from +2 oxidation state in CO to +4 oxidation state in CO₂.
<em><u>Therefore, it is a redox reaction.</u></em>
c) FeO(s) + CO(g) ⟶ Fe(l) + CO₂(g)
In this reaction, Fe accepts electrons and gets reduced from +2 oxidation state in FeO to 0 oxidation state in Fe. Whereas, C loses electrons and gets oxidized from +2 oxidation state in CO to +4 oxidation state in CO₂.
<em><u>Therefore, it is a redox reaction.</u></em>
d) C(s) + O₂(g) ⟶ CO₂(g)
In this reaction, O accepts electrons and gets reduced from 0 oxidation state in O₂ to -2 oxidation state in CO₂. Whereas, C loses electrons and gets oxidized from 0 oxidation state in C to +4 oxidation state in CO₂.
<em><u>Therefore, it is a redox reaction.</u></em>
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e) C(s) + CO₂(g) ⟶ 2CO(g)
In this reaction, C accepts electrons and gets reduced from +4 oxidation state in CO₂ to +2 oxidation state in CO. Whereas, C loses electrons and gets oxidized from 0 oxidation state in C to +2 oxidation state in CO.
<em><u>Therefore, it is a redox reaction.</u></em>
f) CaCO₃(s) ⟶ CaO(s) + CO₂(g)
The oxidation states of Ca, C and O; in the reactant and products are +2, +4 and -2, respectively. Thus the oxidation states of all the elements in this reaction remains same.
<em><u>Therefore, it is NOT a redox reaction.</u></em>
g) CaO(s) + SiO₂(s) ⟶ CaSiO₃(l)
The oxidation states of Ca, Si and O; in the reactant and products are +2, +4 and -2, respectively. Thus the oxidation states of all the elements in this reaction remains same.
<em><u>Therefore, it is NOT a redox reaction.</u></em>
