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 state of O in each reaction:

• In options A, B, D, E: O in \(O_2\) has an oxidation state of 0. In the products (CO, \(SO_2\), \(Na_2O_2\), MgO), the oxidation state of O is negative (e.g., -2 in CO, \(SO_2\), MgO; -1 in \(Na_2O_2\)). So O is reduced (gains electrons), acting as an oxidizing agent.
• In option C: In \(O_2\), O has an oxidation state of 0. In \(OF_2\), O has an oxidation state of +2 (since F is -1, and \(2\times(-1)+x = 0\) gives \(x = +2\)). Here, O is oxidized (loses electrons), so \(O_2\) is acting as a reducing agent, not an oxidizing agent.

Answer:

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