Question

oxygen is acting as an oxidizing agent in all of the following reactions excepta.
2 c(s) + o₂(g) → 2 co(g)
b.
s(s) + o₂(g) → so₂(g)
c.
2 f₂(g) + o₂(g) → 2 of₂(g)
d.
2 na(s) + o₂(g) → na₂o₂(s)
e.
2 mg(s) + o₂(g) → 2 mgo(s)

Explanation:

To determine when oxygen is not an oxidizing agent, we analyze the oxidation state of oxygen in each reaction:

• Option A: In \(O_2\) (oxidation state = 0), in \(CO\), O has oxidation state -2. Oxygen is reduced (gains electrons), so it is an oxidizing agent.
• Option B: In \(O_2\) (0), in \(SO_2\), O is -2. Oxygen is reduced, so it is an oxidizing agent.
• Option C: In \(O_2\) (0), in \(OF_2\), O has an oxidation state of +2 (since F is -1, and \(2(-1) + x = 0 \implies x = +2\)). Oxygen is oxidized (loses electrons), so it is a reducing agent here, not an oxidizing agent.
• Option D: In \(O_2\) (0), in \(Na_2O_2\), O has oxidation state -1. Oxygen is reduced, so it is an oxidizing agent.
• Option E: In \(O_2\) (0), in \(MgO\), O is -2. Oxygen is reduced, so it is an oxidizing agent.

Answer:

C. \(2 F_2(g) + O_2(g)
ightarrow 2 OF_2(g)\)