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

• Option A: In \(O_2\) (oxidation state = 0), in \(CO\), O has -2. Oxygen is reduced (gains electrons), so it is an oxidizing agent.
• Option B: In \(O_2\) (0), in \(SO_2\), O has -2. Oxygen is reduced, so it is an oxidizing agent.
• Option C: In \(O_2\) (0), in \(OF_2\), O has +2 (since F is -1, and \(2\times(-1)+x = 0\) gives \(x = +2\)). Oxygen is oxidized (loses electrons), so it is a reducing agent here.
• Option D: In \(O_2\) (0), in \(Na_2O_2\), O has -1. Oxygen is reduced, so it is an oxidizing agent.
• Option E: In \(O_2\) (0), in \(MgO\), O has -2. Oxygen is reduced, so it is an oxidizing agent.

Only in reaction C, oxygen is oxidized (acts as a reducing agent) instead of an oxidizing agent.

Answer:

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