Salt Analysis for Acid and Base Radicals Ammonium Carbonate

S. No.

EXPERIMENT

OBSERVATION

INFERENCE

1

a)Colour

Colour of the salt is noted

Colourless

Absence of copper and iron salt

b)Appearance

Appearance of the salt is noted

crystaline

May be Sulphate, Nitrate, Chloride

2

Solubility

A little of the salt is shaken with water.

Soluble

May be Sulphate, Nitrate, Chloride or Ammonium Carbonate.

3

Action Of Heat:

A small amount of the salt is heated gently in a dry test tube.

Salt sublimes with evolution

of pungent smelling gas giving dense white fumes with a glass rod dipped in conc HCl.

May be Ammonium

4

Flame Test:

A small amount of the salt is made into a paste with conc. HCl in a watch glass and introduced into the non-luminous part of the Bunsen flame.

No characteristic coloured flame

Absence of Calcium and Barium.

5

Ash Test:

A filter paper is soaked into a paste of the salt with conc. HCl / HNO₃

And Cobalt Nitrate solution in a watch glass and burnt.

No characteristic coloured ash.

Absence of Zinc, Aluminium and Magnesium.

IDENTIFICATION OF ACID RADICALS

6

Action Of Dil Hcl

To a small amount of dilute HCl thesalt is added.

Brisk effervescence of colourless, odourless gas turning Lime water milky.

Carbonate is confirmed.

7

Copper Turnings Test:

A small amount of the salt is heated with Copper Turnings and a few drops of conc. Sulphuric acid.

No reddish brown gas is evolved.

Absence of Nitrate.

8

Action Of NaOH:

A small amount of the salt is heated with Sodium Hydroxide.

Pungent smelling gas forming dense white fumes with a glass rod dipped in conc. HCl and also turns red Litmus paper blue.

Presence of Ammonium

9

Chromyl Chloride Test:

To a small amount of the salt a pinch of Potassium Dichromate is added and heated with few drops of conc. Sulphuric acid.

No Red orange vapours.

Absence of chloride.

PREPARATION OF SODIUM CARBONATE EXTRACT:

A small amount of salt is mixed with twice the amount of sodium carbonate and 20ml of distilled water is added, boiled for 10 minutes, cooled and filtered. The filtrate is called “SODIUM CARBONATE EXTRACT”.

1

Barium Chloride Test:

To a few drops of the extract, dilute Hydrochloric Acid is added until the effervescence ceases and 2 ml of Barium chloride solution is added.

No white precipitate.

Absence of Sulphate

2

Silver Nitrate Test:

To a few drops of the extract dilute Nitric Acid is added until the effervescence ceases and 2 ml of Silver Nitrate solution is added.

No curdy white precipitate,

Absence of Chloride.

3

Lead Acetate Test

To a few drops of the extract dilute acetic acid is added until the effervescence ceases and 2 ml of Lead acetate solution is added

No precipitate

Absence of sulphate

4

Brown Ring Test:

To a few drops of extract dilute Sulphuric acid is added until the effervescence ceases, then freshly prepared FeSO₄ is added and then conctrated Sulphuric acid is added drop by drop along the sides of the test tube.

No brown ring.

Absence of Nitrate.

IDENTIFICATION OF THE BASIC RADICALS PREPARATION OF ORIGINAL SOLUTION:

The orginal solution prepared by dissolving a small amound of salt in water

ZERO GROUP

1

To a few drops of the original solution Sodium Hydroxide and Nessler’s reagent are added.

Reddish brownprecipitate.

Ammonium is confirmed.

GROUP SEPARATION

2

To a few drops of the original solution 2 ml of dilute HCl is added

No characteristic precipitate.

Absence of First Group (Lead).

3

To a few drops of the original solution 1 ml NH₄Cl and 2 ml NH₄OHsolutions are added.

No characteristic precipitate.

Absence of Third Group (Aluminium).

4

To a few drops of the original solution 1 ml NH₄Cl and 2 ml NH₄OHsolutions are added andH₂S gas is passed.

No characteristic precipitate.

Absence of Fourth Group (Zinc).

5

To a few drops of the original solution 1 ml NH₄Cl, 2 ml NH₄OH and 2 ml (NH₄)₂CO₃ solutions are added.

No characteristic precipitate

Absence of Fifth Group (Calcium and Barium).

6

To a few drops of the original solution 1 ml NH₄Cl, 2 ml NH₄OH and 2 ml Di Sodium Hydrogen Phosphate are added.

No characteristic precipitate.

Absence of Sixth Group (Magnesium).

CONFIRMATORY TESTS FOR BASIC RADICALS

1

To a few drops of the original solution Sodium Hydroxide and Nessler’s reagent are added.

Reddish brown precipitate.

Ammonium is confirmed.