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

 

To detect the acid and basic radicals in given salt 

(In Aluminum Chloride).

Experiment – 6

Class – XII

Subject – Chemistry

Aim:-

To detect the acid and basic radicals in given salt (In Aluminum 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:-

3.     Odour:-

4.     Solubility:-

Detection of Acid Radicals

Sr. No	Experiment	Observation	Inference
1.	A pinch of salt was heated with dil. H2So4	No gas evolved	Co3-, So32-, S2- No3-  ions absent
2.	Dry Heating Test The salt was heated in a test tube.	Yellowish green gas evolved with pungent smell.	Cl- may be present.
3.	Heating with Conc. H2So4 The salt was heated with conc. H2So4	Colorless gas was evolved with pungent smell.	Cl- may be present.
4.	Confirmatory Test
(a)	Silver Nitrate test The aqua solution of slat with HNo3 was boiled, cooled and added silver nitrate solution.	A white PPT. formed which was soluble in NH4OH.	Cl- may be present.
	NaCl + AgNo3         à      AgCl ↓ + NaNo3      (white ppt) AgCl + 2 NH4 OH     à     [Ag (NH3)] Cl + 2 H2O         (Soluble complex)
(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 and the lead acetate as added in the solution.	Yellow PPT was observed	Cl- may be present.
	4 NaCl + K2 Cr2 O7 + 6 H2So4    à    4 NaHS4 + 2 Cr2Cl2 + 2 KHSo4 + 3H2O Cr O2 Cl2  + 4 NaOH   à    No2 Cr O4  + 2 H2O + NaCl   (Sodium Chromate) No2 Cr O4  + (CH3 COO)2 Pb  à  Pb Cr O4 ↓ + 2 CH3 COONa (Yellow PPT)

 

Detection of Basic Radicals:-

Sr. No.	Experiment	Observation	Inference
1.	Ø To a part of the O.S. added 1 – 2 ml of dil HCl.   Ø Through a part of the above solution passed H2S gas. Ø To the remaining solution added a pinch of solid ammonium chloride. Boiled the solution, cooled it and added excess of ammonium hydroxide solution.	No PPT formed   No PPT formed     White PPT formed	Group I absent   Group II absent
	Confirmatory Test
(a)	Lake test Dissolve the white ppt in dil. HCl and added two drops of blue litmus solution to this added NH4OH drop wise till blue change into red.	Blue PPt float in the colorless solution.	Al3+  confirmed
	Al (OH)3 + 3 HCl  à    Al Cl3­ + 3 H2O Al Cl3 + 3 NH4OH   à   3 NH4Cl + Al (OH)3

 

Conclusion:-

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

Acid Radical :           Cl^-

Basic Radical:           Al³⁺