Question

Balance the following equations by oxidation-reduction methods; note that three elements change oxidation state. Co(NO₃)₂(s)⟶Co₂O₃(s)+NO₂(g)+O₂(g)

a. 2Co(NO₃)₂(s) → Co₂O₃(s) + 4NO₂(g) + 3O₂(g)
b. Co(NO₃)₂(s) → Co₂O₃(s) + 2NO₂(g) + O₂(g)
c. 3Co(NO₃)₂(s) → Co₂O₃(s) + 6NO₂(g) + 5O₂(g)
d. 4Co(NO₃)₂(s) → Co₂O₃(s) + 8NO₂(g) + 6O₂(g)

Answer 1

To balance the equation b. Co(NO₃)₂(s) ⟶ Co₂O₃(s) + NO₂(g) + O₂(g) using oxidation-reduction methods, the balanced equation is 4Co(NO₃)₂(s) ⟶ 2Co₂O₃(s) + 4NO₂(g) + 5O₂(g).

Step-by-step explanation:

To balance the equation b. Co(NO₃)₂(s) ⟶ Co₂O₃(s) + NO₂(g) + O₂(g) using oxidation-reduction methods, we need to assign oxidation states to all the atoms involved. Cobalt (Co) has an oxidation state of +2 in Co(NO₃)₂(s), +3 in Co₂O₃(s), and 0 in Co(s).

Nitrogen (N) has an oxidation state of +5 in NO₃ and +4 in NO₂. Oxygen (O) has an oxidation state of -2 in NO₃ and NO₂ and -1 in O₂. By considering the changes in oxidation states, we can write the balanced equation as 4Co(NO₃)₂(s) ⟶ 2Co₂O₃(s) + 4NO₂(g) + 5O₂(g).