oxygen is acting as an oxidizing agent in all of the following reactions except\n\na. $2\\text{c}(\\text{s})…

Explanation:

Step1: Define oxidizing agent

An oxidizing agent gains electrons and its oxidation state decreases.

Step2: Analyze oxidation states in A

In $2\text{C} + \text{O}_2 \rightarrow 2\text{CO}$, O changes from $0$ to $-2$. It is an oxidizing agent.

Step3: Analyze oxidation states in B

In $\text{S} + \text{O}_2 \rightarrow \text{SO}_2$, O changes from $0$ to $-2$. It is an oxidizing agent.

Step4: Analyze oxidation states in C

In $2\text{F}_2 + \text{O}_2 \rightarrow 2\text{OF}_2$, F is more electronegative. O changes from $0$ to $+2$. O is oxidized, making it a reducing agent.

Step5: Analyze oxidation states in D

In $2\text{Na} + \text{O}_2 \rightarrow \text{Na}_2\text{O}_2$, O changes from $0$ to $-1$. It is an oxidizing agent.

Step6: Analyze oxidation states in E

In $2\text{Mg} + \text{O}_2 \rightarrow 2\text{MgO}$, O changes from $0$ to $-2$. It is an oxidizing agent.

Answer:

C. $2\text{F}_2(\text{g}) + \text{O}_2(\text{g}) \rightarrow 2\text{OF}_2(\text{g})$