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 \( \ce{O2} \), the oxidation state of O is 0. In \( \ce{CO} \), the oxidation state of O is -2. Oxygen is reduced (oxidation state decreases), so it acts as an oxidizing agent.
• Option B: In \( \ce{O2} \), O has an oxidation state of 0. In \( \ce{SO2} \), O has an oxidation state of -2. Oxygen is reduced, so it acts as an oxidizing agent.
• Option C: In \( \ce{O2} \), O has an oxidation state of 0. In \( \ce{OF2} \), O has an oxidation state of +2 (since F is -1). Oxygen is oxidized (oxidation state increases), so it acts as a reducing agent, not an oxidizing agent.
• Option D: In \( \ce{O2} \), O has an oxidation state of 0. In \( \ce{Na2O2} \), O has an oxidation state of -1. Oxygen is reduced, so it acts as an oxidizing agent.
• Option E: In \( \ce{O2} \), O has an oxidation state of 0. In \( \ce{MgO} \), O has an oxidation state of -2. Oxygen is reduced, so it acts as an oxidizing agent.

Answer:

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