Dry Test: Examination of Salt

A number of tests can be carried out using the powdered salt. The information thus obtained often provides a clue to the presence or absence of certain radicals. With their knowledge, the course of wet analysis may be shortened or modified.

Under physical examination, you have to examine the colour, smell and the density of salt.

Colour

Blue: Copper salt may be present

Green (light or dark): Copper, nickel and ferrous salt may be present

Yellow: Ferric salt may be present

Pink: Manganese salt may be present

Buff (pale yellow-brown): Manganese salt may be present

White: Salts of remaining cations may be present (Ca²⁺, NH⁴⁺, Pb²⁺, Zn²⁺)

Smell

Rub a pinch of salt with the help of a spatula on a watch glass.

Smell of ammonia: Ammonium salt may be present

Smell of rotten eggs: Sulphide salt may be present 

Density

Salt is light: Carbonates of zinc and calcium may be present