ACIDIC RADICALS ( DILUTE SULPHURIC ACID GROUP)

 DATE

                                                 EXPERIMENT NO._________

Aim :  To test the presence of Carbonate (CO32- ) in the given salt.

S.NO.	EXPERIMENT	OBSERVATION	INFERENCE
1.	Physical tests: (i) Colour  (ii) Odour (iii) Solubility
2.	Take 1g of salt in a dry test tube and 4-5 ml of dil.H2SO4 .	Colourless , odourless gas with brisk effervescence is evolved.	May be Carbonate , CO32-.
3.	Pass the gas evolved through the lime water.	Lime water turns milky.	CO32- is confirmed.
4.	Pass CO2 for a longer time.	Milkiness disappeares.	CO32- is confirmed.
5.	Take aqueous solution of the given salt , then add MgSO4 solution.	White precipitate is formed.	CO32- is confirmed.

RESULT  : The given salt contains  Carbonate (CO32- )  in it .

REACTIONS INVOLVED  :---------

(i)   CO32- (s)  + dil.H2SO4  (aq)  ----------------→    CO2 (g) +  H2O(l)  + SO42- (aq)

(ii)  Ca(OH)2 (aq)  + CO2 (g)     ----------------→      CaCO3 (s)  + H2O (l)

                                                                                    White ppt

(iii)  CaCO3 (s)  + H2O (l) +  CO2 (g)   ----------------→    Ca(HCO3)2 (aq)

(iv)  CO32- (aq)  + MgSO4  (aq)            ----------------→  MgCO3 (s)  + SO42- (aq)

DATE

                                                 EXPERIMENT NO._________

Aim  : To test the presence of Sulphite ( SO32-)  in the given salt.

S.No.	EXPERIMENT	OBSERVATION	INFERENCE
1.	Physical tests: (i) Colour  (ii) Odour (iii) Solubility
2.	Take 1g of salt in a dry test tube and 4-5 ml of dil.H2SO4 .	Colourless  gas with the smell of burning sulphur is evolved.	May be  Sulphite ( SO32-) .
3.	Take salt solution in a test tube & add  K2Cr2O7 solution and 2,3 drops of dil. H2SO4 .	Green colouration is obtained.	SO32-  is confirmed.
4.	Take aqueous solution of the given salt & add BaCl2 solution to it.	White ppt is obtained which dissolves in dil. HCl.	SO32-  is confirmed.
5.	Take aqueous solution of the given salt & add a few drops of acidified KMnO4 solution.	Pink colour of KMnO4 is discharged.	SO32- is confirmed.

RESULT  : The given salt contains   Sulphite (SO32- )  in it .

REACTIONS INVOLVED  :---------

(i)   SO32- (s) +  dil.H2SO4  (aq)   ----------------🡪    SO2 (g) +  H2O(l)  + SO42- (aq)

(ii)   K2Cr2O7 (aq) + 3SO32- (aq) +  4H2SO4  (aq) ----------------🡪    Cr2(SO4)3 (aq)  +  

                                                                                                             4SO42- (aq)   +4H2O(l)

 (iii)  SO32- (aq) +  BaCl2   (aq) ----------------🡪   BaSO3 (s)  + Cl – ( aq)

        BaSO3 (s)  + 2HCl (aq)     ----------------🡪   BaCl2  (aq)  + H2O(l)  + SO2 (g)

(iv)  5SO32- (aq) +  2KMnO4  (aq) +  3H2SO4  (aq)   -------------🡪  2MnSO4 (aq) +   

                                                                                                            6SO42-(aq) + 3H2O(l)

DATE

                                                 EXPERIMENT NO._________

Aim :  To test the presence of  Sulphide ( S2-)  in the given salt.

S.No.	EXPERIMENT	OBSERVATION	INFERENCE
1.	Physical tests: (i) Colour  (ii) Odour (iii) Solubility
2.	Take 1g of salt in a dry test tube and 4-5 ml of dil.H2SO4 .	Colourless  gas with rotten eggs smell  is produced.	May be  S2-.
3.	SODIUM NITROPRUSSIDE TEST : Take aqueous solution of the given salt & add Sodium Nitroprusside solution to it.	A violet colouration is obtained.	S2-  is confirmed.
4.	LEAD ACETATE TEST : Take aqueous solution of the given salt ,add acetic acid  & Lead acetate solution to it.	Black ppt is obtained.	S2- is confirmed.
5.	SILVER NITRATE TEST : To aqueous solution of the given salt ,add AgNO3 solution.	Black ppt is obtained which is soluble in HNO3.	S2- is confirmed.

RESULT  : The given salt contains  Sulphide ( S2-)    in it .

REACTIONS INVOLVED  :---------

(i)   S2- (s)  + dil.H2SO4  (aq)                 ----------------🡪 H2S  (g)   + SO42- (aq)

(ii)  S2- (aq)   + Na2[Fe(CN)5NO]  (aq)     ----------------🡪    Na4 [Fe(CN)5NOS] (aq) 

                        Sod.Nitroprusside                                           Violet colouration                       

(iii)  S2- (aq)   + (CH3COO)2Pb (aq)      ----------------🡪       PbS (s) + 2CH3COO- (aq)

                                                                                             Black ppt

(iv)  S2- (aq)   + AgNO3   (aq)                        ---------------🡪      AgS (s) + NO3-(aq)

                                                                                            Black ppt

  

DATE

                                                 EXPERIMENT NO._________

Aim :  To test the presence of  Nitrite ( NO2- ) in the given salt .

S.No.	EXPERIMENT	OBSERVATION	INFERENCE
1.	Physical tests: (i) Colour  (ii) Odour (iii) Solubility
2.	Take 1g of salt in a dry test tube and 4-5 ml of dil.H2SO4 .	Light brown coloured gas is evolved.	May be  NO 2-.
3.	FERROUS SULPHATE TEST :------ Take aqueous solution of the given salt & add a few drops of  acetic acid & FeSO4 solution to it.	A  dark brown or black  colouration is obtained.	NO 2- is confirmed.
4.	STARCH IODIDE TEST :---- Take aqueous solution of the given salt ,add dil.H2SO4 and a few drops of KI solution, followed by 1 ml of starch solution.	A dark blue colouration is formed.	NO 2- is confirmed.
5.	POTASSIUM PERMANGNATE TEST :---- Take aqueous solution of the given salt & add a few drops of acidified KMnO4 solution.	Pink colour of KMnO4 is discharged.	NO 2- is confirmed.

RESULT  : The given salt contains Nitrite ( NO2- )   in it .

REACTIONS INVOLVED  :---------

(i)  3NO2- (s)  + 3H2SO4  (aq)    ----------------🡪  2NO (g)   + 3HSO4- (aq)  +  

                                                                                     NO3- (aq)   + H2O(l)                                                                                 

(ii)  NO2- (aq)   + CH3COOH (aq)    -------------------🡪   CH3COO- (aq) +  HNO2 (l)

                                 3 HNO2 (l)       -------------------🡪     HNO3 (l) + 2NO (g) + H2O (l)

                         FeSO4 (aq)  + NO(g)      -------------------🡪     FeSO4 .NO (aq)     

                                                                                            Black colouration 

      

(iii) 2 NO2-  (aq)  + 2H2SO4  (aq)  + 2KI (aq)  ----------------🡪  2NO (g) + 2SO42-(aq)

                                                                                                       + I2  (g) + 2H2O (l)

                            I2(g)  + Starch  (aq)     --------------🡪     Deep blue colouration

(iv)  5NO2-   (aq) +  2KMnO4  (aq) +  3H2SO4  (aq)   -----------🡪  SO42-(aq) + 3H2O(l) + 

                                                                                                   5KNO3 (aq) +  2MnSO4 (aq)