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Chemistry Exam I: Oxidation: Loss of electrons by a species (increase oxidation #)Reduction: Gain of electrons by a species (decrease oxidation #)Oxidizing Agent: electron acceptor, species is reducedReducing agent: electron donor, species is oxidizedBalancing Redox Reactions:1)Write out all oxidation numbers to see what’s being oxidized, reduced2)Write out half reactions3)Balance Oxygens by adding H2O and balance Hydrogens by adding H+4)For acidic solutions: Balance net charges by adding electrons5)Multiply equations so electrons cancel out6)Add two half reactions7)Add OH- to make water and cancel out H+8)Cancel out what you can (Especially water molecules)Types of Redox reactions: oDirect: No external circuit (no useful electric current)oIndirect: External circuit (useful current, external wire used)Electrochemical cells: Apparatus that allows a redox reaction to occur by transferring electrons through an external connector (circuit).oGalvanic/voltaic cell: Produces electrical energy. Chemical change produces electric current. DeltaGrxn<0. Product favored reaction. Ex. BatteriesoElectrolytic cell: Requires electrical energy. Electrical current used to cause chemical change in a non-spontaneous reaction. DeltaGrxn>0.