Oxidizing and Reducing Agents: Definitions and Examples in Chemistry

Is an oxidizing agent reduced or oxidized?

Reduced (it gains electrons)

Is a reducing agent reduced or oxidized?

Oxidized (it loses electrons)

Is MnO4- (permanganate) an oxidizer or reducer?

Oxidizer (gains electrons to become Mn2+, MnO2, or MnO4 2-)

Is Cr2O7 2- (dichromate) an oxidizer or reducer?

Oxidizer (gains electrons to become Cr3+)

Is HNO3 (nitric acid) an oxidizer or reducer?

Oxidizer (gains electrons to become NO2 or NO gas)

Is hot, concentrated H2SO4 an oxidizer or reducer?

Oxidizer (gains electrons to become SO2 gas)

Are free halogens (F2, Cl2, Br2, I2) oxidizers or reducers?

Oxidizers (gain electrons to become halide ions like Cl-)

Are ClO3- (chlorate) and ClO- (hypochlorite) oxidizers or reducers?

Oxidizers (gain electrons to become Cl-)

Are neutral free metals (Na, Mg, Zn, Cu) oxidizers or reducers?

Reducers (lose electrons to become metal cations)

Are halide ions (Cl-, Br-, I-) oxidizers or reducers?

Reducers (lose electrons to become free halogens like Cl2)

Is sulfite (SO3 2-) an oxidizer or reducer?

Reducer (loses electrons to become sulfate SO4 2-)

Is nitrite (NO2-) an oxidizer or reducer?

Reducer (loses electrons to become nitrate NO3-)

Is oxalate (C2O4 2-) an oxidizer or reducer?

Reducer (loses electrons to become CO2 gas)

Is Fe2+ an oxidizer or reducer when forming Fe3+?

Reducer (loses an electron)

When H2O2 turns into H2O, is it acting as an oxidizer or reducer?

Oxidizer (oxygen is reduced from -1 to -2)

When H2O2 turns into O2 gas, is it acting as an oxidizer or reducer?

Reducer (oxygen is oxidized from -1 to 0)

Which common oxyanions are strong oxidizers?

Permanganate (MnO4-), Dichromate (Cr2O7 2-), Nitrate (NO3-), Chlorate (ClO3-)

Which common polyatomic ions are strong reducers?

Sulfite (SO3 2-), Nitrite (NO2-), Oxalate (C2O4 2-)