Indicate which of the following chemical reaction are redox reactions: a. 2PbS+ 30 2Pb0 + 250 b. CH+202 CO2 + 2HO c. 4Fe +302Fe:0; d. 2AgNO, CuCl Cu(NO)2 + 2AgCl e. FeCl + 2NaOH Fe(OH) + 2NaCl 4. Balance the following redox reaction. Remember that you need to balance both the atoms and the charge. Start by writing the oxidation number of each element above or below the equation to see how the oxidation numbers change in this reaction. Balance the reaction: H+ + TCO + HCOOHT+ HO + CO O A