Chem ch.30.6 common oxidizing agents and reducing agents

acidified potassium permanganate solution

MnO4^-

oxidizing agent

main change: MnO4- → Mn2+

purple → colourless (or very pale pink)

acidified potassium dichromate solution

CrO7^2-

oxidizing agent

main change: CrO7^-2 → Cr3+

orange → green

dilute nitric acid

NO3^- (dilute)

oxidizing agent

main change: NO3^- → NO

colourless → colourless

concentrated nitric acid

NO3^- (concentrated)

oxidizing agent

main change: NO3^- → NO2

colourless → brown

concentrated sulphuric acid

H2SO4

oxidizing agent

main change: H2SO4 → SO2

colourless → colourless

oxygen

O2

oxidizing agent

main change: O2 → OH- / O^2-

colourless → colourless

chlorine

Cl2

oxidizing agent

main change: Cl2 → Cl^-

yellowing green → colourless

Br2

bromine (in aqueous solution)

oxidizing agent

main change: Br2 → Br^-

yellow/brown → colourless

Ag^+

postive ion

oxidizing agent

main change: positive ion → metal atom

e.g. Ag^+ → Ag

colourless → silvery

Fe^3+

iron (III) salts

oxidizing agent

main change: Fe^3+ → Fe^2+

yellow → pale green

Na

metal atom

reducing agent

main change: metal atom → positive ion

e.g. Na → Na^+

grey → colourless

SO2

sulphur dioxide

reducing agent

main change: SO2 → SO4^2-

colourless → colourless

SO3^2-

sulphites

reducing agent

main change: SO3^2- → SO4^2-

colourless → colourless

Fe^2+

iron (II) salts

reducing agent

main change: Fe^2+ → Fe^3+

pale green → yellow

H2

hydrogen

reducing agent

main change: H2 → H+

colourless → colourless

C

carbon

reducing agent

main change: C → CO / C → CO2

black → colourless

I^-

iodides

reducing agent

main change: I^- → I2

colourless → brown (iodine dissolved in water is brown)