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 check the oxidation state change of oxygen. An oxidizing agent is reduced (oxidation state decreases).

• In option A: C goes from 0 to +2 (oxidized), O in \(O_2\) (0) goes to -2 in CO (reduced) → O is oxidizing agent.
• In option B: S goes from 0 to +4 (oxidized), O in \(O_2\) (0) goes to -2 in \(SO_2\) (reduced) → O is oxidizing agent.
• In option C: F in \(F_2\) (0) goes to -1 in \(OF_2\) (reduced), O in \(O_2\) (0) goes to +2 in \(OF_2\) (oxidized) → O is a reducing agent (not oxidizing agent).
• In option D: Na goes from 0 to +1 (oxidized), O in \(O_2\) (0) goes to -1 in \(Na_2O_2\) (reduced) → O is oxidizing agent.
• In option E: Mg goes from 0 to +2 (oxidized), O in \(O_2\) (0) goes to -2 in MgO (reduced) → O is oxidizing agent.

Answer:

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