I'm not able to solve this question. Have my exam tomorrow

I'm not able to solve this question. Have my exam tomorrow 11. Identify the substance oxidise, substance reduced, oxidizing agent and reducing agent in the following reactions: i) Pb304+8HC1— 3PbC12+ C12+ 41120 ii) 2Mg+ 0—2MgO iii)V205+ 5Ca—2V+ 5CaO iv)3Fe+ 4HO— F 304+4H2