To detect the acid and basic radicals in given salt (In Calcium Chloride).

Experiment – 10

Class – XII

Subject – Chemistry

Aim:-

To detect the acid and basic radicals in given salt (In Calcium Chloride).

Apparatus:-

Test tube, test tube stand, test tube holder, burner, beaker, litmus paper, match box etc.

Physical Characteristic:-

1.     State: - solid crystalline

2.     Color:- Colorless

3.     Odour:- No specific odour

4.     Solubility:-  Soluble in cold water

Detection of Acid Radicals

Sr. No	Experiment		Observation	Inference
1.	Dry heating test: ­The salt was heated test tube.		Yellowish green gas was evolved with pungent smell.	Cl- may be present
2.	Heating with dil. H2So4 The salt was heated with conc. H2So4.		No gas evolved	Co3-, So3-, S2- No2- CH3COO-  ions absent
3.	Heating with conc. H2So4 Salt was heated with conc. H2So4		Colorless gas was evolved with pungent smell	Cl- may be present
	Confirmatory test:
a.	Silver nitrate Test: Boiled the aqua solution of salt with HNo3, cooled it and added silver nitrate solution.		A white ppt was formed which was insoluble in NH4OH	Cl-  confirmed
	NaCl + AgNo3  à     AgCl + NaNO3 AgCl  +  2 NH4OH    à     [Ag ( NH3)2] Cl  + 2 H2O
b.	Chromyl Chloride test: A small quantity of salt was mixed with potassium dichromate and added conc. H2So4. Heated the test tube and passed the vapors through a NaOH solution.  Added acetic acid to the yellow solution obtained & then lead acetate was added in solution.	Yellow ppt was observed			Cl-  Confirmed
	4 NaCl + K2Cr2O7 + 3 H2So4    à    2 Na2 Cr O4  + 2 H2O + 2 NaCl Na2Cr O4  +  (CH3COO)2 Pb   à   Pb Cr O4 ↓  + 2 CH3 COO Na

 

Detection of Basic Radicals:-

Sr. No.	Experiment		Observation		Inference
a.	O.S. was added with dil. HCl.		No PPT formed		Group I radical absent
b.	O.S. was added with dil. HCl and H2S was passed.		No PPT formed		Group II radical absent
c.	To the remaining solution added a pitch of solid ammonium chloride, boiled the solution, cooled it and added excess of ammonium hydroxide solution.		No PPT was obtained		Group III radical absent
d.	O.S. was added with NH4Cl and NH4OH followed by H2S gas.		No PPT formed		Group IV  absent
e.	To remaining ammonium chloride solution added ammonium carbonate solution.		No PPT obtained		Group V absent
	Confirmatory test:-   Dissolved the ppt in hot dil. Acetic acid.
1.	Test for Ba2+ To one part of the solution added few drops of potassium chromate solution.	No PPT formed		Ba2+ absent
2.	Test for Sr2+ To second part of the solution added 1 ml of ammonium sulphate solution.	No PPT formed		Sr2+ absent
3.	Test for Ca2+ To third part of the solution added ammonium oxalate solution.	White ppt formed		Ca2+ present
4.	Flame test: Placed small amount of salt on platinum wire loop & introduced it into flame	Brick red flame		Ca2+ present

 

Conclusion:-

On the basis of above test, we conclude that given salt contain.

Acid Radical:            Cl^-

Basic Radical:           Ca²⁺