Colour of ions in aqueous solution

Ions Colour of ions in aqueous

solution

All Group I, II & III metal ions Colourless

NH4+ Colourless

Pb2+, Zn2+ Colourless

Cu2+ Blue or green

Fe2+ Green

Fe3+ Yellow or brown

Co2+ Pink

Ni2+ Green

Cr3+ Green

Mn2+ Very pale pink or colourless

All halide ions: F-, Cl-, Br-, I- Colourless

Most anions except MnO4-, CrO4

2-, Cr2O72- Colourless

MnO4- Purple

CrO42- Yellow

Cr2O72- Orange

Colour of halogens and halides

Free elements In aqueous

solution

In organic

solvent

Halide ions in

aqueous solution

Silver halides

ppt

Cl2(g) greenish

yellow gas

Greenish yellow Greenish yellow

Colourless

AgCl white

Br2(l) dark red liquid Brown Red-orange AgBr creamy

I2(s) black solid Brown Purple AgI yellow

Colour of metal oxides

Metal oxides Colour of metal oxides

All metal ions that is colourless in

aqueous solution except PbO

White

CuO Black

Cu2O Red

HgO Red

Fe2O3 Black

Fe3O4 (iron (II) iron(III) oxide) Black

PbO Yellow

FeS Black

Solubility of salts in aqueous solution

Soluble Insoluble

All common K+, Na+ and NH4+

All NO3- and NO2

-

All HCO3-

All Cl-, Br- and I- except AgCl, AgBr, AgI

All sulphate except CaSO4, BaSO4, PbSO4

K2CO3, Na2CO3, (NH4)2CO3 All other common carbonate

S2- of Group I and Group II metals All other sulphides

KOH, NaOH

Ca(OH)2 is slightly soluble

All other common metal hydroxides

Flame test

Metal ions contain Flame colour

Sodium Golden yellow

Potassium Lilac

Copper Blue or green

Calcium Brick red

Testing of gases

Gases Test with positive result

Oxygen Relights glowing splint

Hydrogen Burns with ‘pop’ sound

Carbon

dioxide

Turns lime water milky

Turns hydrogencarbonate indicator from red to yellow

Chlorine Turns moisten blue litmus blue than bleaches it

Sulphur

dioxide

Turns filter paper soaked with acidified potassium dichromate from orange to green.

Turns filter paper soaked with acidified potassium permanganate from purple to

colourless.

Ammonia Turn moisten red litmus paper blue.