2. To analyse the given salt for Acidic and Basic radicals. (NH4)2CO3.

Aim:- To analyse the given salt for acidic and basic radicles.

Physical Examination Test:-

Colour - White

Smell - Ammonical smell

Appearance - Amorphus.

Dry Heating Test:-

Procedure	Objective	Inference
Take a small amount of salt in dry test tube and heat.	Gas evolved with ammonical smell	NH4+ may be present

.

Dilute Sulfuric Acid Test:-

	Inference
Observation	Gas evolved	Possible radicals
Colourless, odourless gas with brisk effervescence which turns lime water milky.	CO2	CO32-

Confirmation of acid radicals by wet tests:-

The acid radical indicated by dilute H₂SO₄ or concentrated H₂SO₄ test in further confirmed by wet test.

Preparation of solution of the salt for wet test of acid radicals: Aqueous solution or ‘Water extract’. Shake a little of the salt with water. If the salt dissolves, this aqueous solution obtained is used for the wet tests of acid radicals and is called ‘Water extract’ or ‘W.E’.

Procedure	Observation	Inference
Dilute HCl test: To one portion of the solution add HCl.	Brisk effervescence and evolution of colourless, odourless gas, which turns lime water milky.	CO32- is present.
Magnesium sulfate test: Add magnesium sulfate to one portion of solution.	Formation of white precipitate.	CO32-  is present.

Wet tests for Basic radicals (Cations)

Preparation of solution for wet tests of basic radicals: If the salt is insoluble in distilled water as well as dilute HCl, try to dissolve it in concentrated HCl, first in cold and then on heating. The clear solution thus obtained is labelled as original solution (O.S).

Analysis of group-Zero (NH₄⁺)

Procedure	Observation	Inference
Salt solution is heated with sodium hydroxide.	Ammonical gas is evolved.	NH4+ may be present.
Pass the gas through nessler’s reagent.	Brown precipitate is formed.	NH4+ is present.

Results:-

Acid Radicals:- CO₃²⁺

Basic Radicals:- NH₄⁺

Therefore, The salt is (NH₄)₂CO₃.