Final answer:
In the reaction C3H4 + 2H₂ → C3H8, H₂ is the oxidizing agent and C3H4 is the reducing agent.
Step-by-step explanation:
In the reaction C3H4 + 2H₂ → C3H8, the oxidizing agent is H₂ and the reducing agent is C3H4.
The oxidizing agent is the substance that is reduced and causes another substance to be oxidized. In this reaction, H₂ is reduced to form C3H8, so it is the oxidizing agent.
The reducing agent is the substance that is oxidized and causes another substance to be reduced. In this reaction, C3H4 is oxidized to form C3H8, so it is the reducing agent.