Question

oxygen is acting as an oxidizing agent in all of the following reactions except a. \\(2 c(s) + o_2(g) \
ightarrow 2 co(g)\\) b. \\(s(s) + o_2(g) \
ightarrow so_2(g)\\) c. \\(2 f_2(g) + o_2(g) \
ightarrow 2 of_2(g)\\) d. \\(2 na(s) + o_2(g) \
ightarrow na_2o_2(s)\\) e. \\(2 mg(s) + o_2(g) \
ightarrow 2 mgo(s)\\)

Explanation:

To determine in which reaction oxygen is not acting as an oxidizing agent, we analyze the oxidation states of oxygen in each reaction:

• Option A: In \( \ce{O2} \) (oxidation state = 0), in \( \ce{CO} \), oxygen has an oxidation state of -2. Oxygen is reduced (gains electrons), so it acts as an oxidizing agent.
• Option B: In \( \ce{O2} \) (0), in \( \ce{SO2} \), oxygen is -2. Oxygen is reduced, so it acts as an oxidizing agent.
• Option C: In \( \ce{O2} \) (0), in \( \ce{OF2} \), oxygen has an oxidation state of +2 (since fluorine is -1 and the compound is neutral: \( x + 2(-1) = 0 \Rightarrow x = +2 \)). Oxygen is oxidized (loses electrons), so it acts as a reducing agent, not an oxidizing agent.
• Option D: In \( \ce{O2} \) (0), in \( \ce{Na2O2} \), oxygen has an oxidation state of -1. Oxygen is reduced, so it acts as an oxidizing agent.
• Option E: In \( \ce{O2} \) (0), in \( \ce{MgO} \), oxygen is -2. Oxygen is reduced, so it acts as an oxidizing agent.

Answer:

C. \( \ce{2 F2(g) + O2(g) → 2 OF2(g)} \)