Qualitative Analysis – ions identification

Identification of Ions

There are 10 cations and 4 anions to be studied:

Cation

Sodium       Na+   Iron (II)       Fe2+

Calcium      Ca2+ Iron (III)      Fe3+

Magnesium Mg2+ Lead(II)       Pb2+

Aluminium Al3+  Copper (II)  Cu2+

Zinc   Zn2+ Ammonium NH4+

Anion

Chloride ion Cl–

sulphate ion SO42-

nitrate ion    NO3–

carbonate ion        CO3–

Steps in qualitative analysis

qualitative

Colour of Ions

Salt or metal oxide Solid Aqueous solution

Salt of Sodium, Calcium, Magnesium, Aluminium, zinc, Lead, ammonium   White         Colourless

Salt of Chloride, sulphate, nitrate, carbonate White         Colourless

Salt of Copper(II) –

Copper(II) Carbonate      Green –

Copper(II) sulphate, Copper(II) nitrate, Copper(II) chloride       Blue  Blue

Copper(II) oxide   Black –

Salt of Iron (II):

Iron(II) sulphate; Iron(II) nitrate; Iron(ID chloride  Green Green

Salt of  Iron (III):

Iron(III) sulphate; Iron(III) nitrate; Iron(III) chloride        Brown        Brown

Zink oxide   Yellow when it is hot and white when it is cold.     –

Lead(II) oxide-      Brown when it is hot and yellow when it is cold.    –

Magnesium oxide, Aluminium oxide  White Insoluble

Potassium oxide, Sodium oxide, Calcium oxide     White Colourless