TO DETECT ACID RADICAL PRESENT IN GIVEN INORGANIC SALT SAMPLE BY WET (A1, A2, A3 )

APPARATUS REQUIRED

i)  Test tube

ii) Test tube holder

iii) Test tube stand

iv) Tong

CHEMICAL REQUIRED

i) Silver nitrate

ii) Barium chloride

iii) Ferrous sulphate solution

iv) Conc. H₂SO₄

THEORY:

Qualitative analysis of an inorganic salt is simply the detection of acid and basic radicals of salt by suitable method.

A salt is simply the compound which is formed by complete or partial neutralization of acid by a base salt are strong electrolytes When dissolved in water almost completely dissociated into positively and negatively charged ions.

Acid radicals are simply the electronegative radical obtained from acid in the salt. For example: Cl^– ,NO₃^—, SO₄^—, CO₄^— but the exception is OH- ion which is only electronegative radical not acid radical.

Wet ways:

The ways performed in the form of solution by dissolving salt,

During wet tests the radicals are detected from the solution generally, by observing the characteristic color of the precipitate or solution or gas formed after the ionic interaction with suitable reagents.

SAMPLE NO: A₁

PHYSICAL PROPERTIES:

State————-> crystalline solid

colour ————>  white

Odour ————> characteristics

Solubility ———-> soluble in water

PROCEDURE:

The original solution (0.5) was made by dissolving the given sample in water and different tests were performed as.

OBSERVATION TABLE AT: (A₁)

1. AgNO₃ test:

Experiment	Observation	Inference
Few ml of prepared solution was taken in the test tube and a few drops of AgNO3 solution was added.	No ppt was observed.	Absence of halideion.

2. BaCl2 test

Experiment	Observation	Inference
Few ml of original solution was taken in test tube and few drops of BaCl2 solution was added.	White ppt was formed which was readily soluble indil HCl with CO₂.	Presence of CO3 —.

TEST REACTION

For carbonate CO₃ ^— ions.

CO₃ ^— + BaCl₂ —————> BaCO₃   ↓+2Cl^– 

(white ppt)

BaCO₃ + 2HCl —————> BaCL₂ + H₂O + CO₂

RESULT

Hence, the given inorganic salt sample (A₁) contains CO₃ ^— at acid radical.

SAMPLE NO: A₂

Physical properties:

State ———–> crystalline solid

Colour ———->  Blue

Odour ———–> Character 

Solubility ———>  Soluble in water

OBSERVATION TABLE FOR SAMPLE NO: A₂

1. AgNO₃ test:

Experiment	Observation	Inference
Few mt of prepared solution was taken in the test tube and a few drops of AgNO3 solution was added.	No ppt was observed.	Absence of Cl–, Br, I.

2. BaCl test:

Experiment	Observation	Inference
Few ml of the original solution was green in the test tube and a few drops of Ba Cl2 solution was added.	White ppt was informed which was insoluble in dil. HCl.	Presence of SO4—.

TEST REACTION

For sulphate SO₄^— test

SO₄^— + BaCl₂ ———-> BaSO₄ ↓+ 2Cl^– 

BaSO₄ + HCl ———-> No reaction 

RESULT

Hence, the given inorganic salt sample contains SO₄^— as acid radical.

SAMPLE NO: A₃

PHYSICAL PROPERTIES:

State ———->  crystalline solid

Colour ———>  reddish red

Odour ———-> characteristics

solubility  ———> soluble in water

OBSERVATION TABLE FOR SAMPLE NO :A₃

1. AgNO₃ test:

Experiment	Observation	Inference
Few ml of prepared solution was taken in test tube and few drops of AgNO3 solution was added.	No. ppt was observed	Absence of halideions.

2. BaCl₂ test:

Experiment	Observation	Inference
Few ml of the original solution was taken in the test tube and a few drops of BaCl2 solution was added.	No ppt was observed.	Absence of SO3—and CO3–.

3. Ring test:

Experiment	Observation	Inference
Few ml of original solution was taken in a test tube and about double the volume of conc. H2SO4 was added slowly drop by drop with constant shaking and freshly prepared FeSO4 solution was added slowly from side of inclined tube without disturbing them.	A brown ring Between two liquid layers were seen.	presence of nitrate ion (NO3–)

TEST REACTION

NO₃^– + H₂ SO₄ —————-> HNO₃ +HSO₄ ^–

6FeSO₄ + 2HNO₃ + 3H2SO₄ ————–> 3Fe (SO₄ )₃ + 2NO + 4H2O

FeSO₄ + NO ————–> FeSO₄ .NO

       [Nitrosyl Ferrous Suphate]

                                 [Brown ring]

RESULT:

Hence, the given inorganic salt sample NOA₃ contains NO₃ as acid radical.

CONCLUSION:

In this way, the acid radical present in a given salt sample can be deserved by wet ways.

PRECAUTIONS:

1. Apparatus should be neat and clean.

2. Reagents used should be an accurate amount.

3. Conc. H₂SO₄ should be handled carefully.