KENDRIYA VIDYALAYA CLRI Class 12 Chemistry
DISTINGUISHING TEST BETWEEN ORGANIC COMPOUNDS
1)Methanol and Ethanol
Ethanol gives iodoform test.where as methanol does not
CH3CH2OH +NaOI NaOH,I2 CH3CHO+NaI+H2O
CH3CHO+3NaOI-CHI3+HCOONa+2NaOH
CH3OH+-NaOI---.>No reaction
2)Ethanol and Phenol
Ethanol gives iodofrm test,where as phenol does not
CH3CH2OH+NaOICHI3+HCOONa+NaOH
C6H5OH+NaOINO reaction
Phenol gives violet colour with neutralFeCl3
3C6H5OH+FeCl3(C6H5O)3Fe+3H
3)Formaldehyde and Acetaldehyde
Formaldehyde gives yellow ppt with an alkaline solution of iodine
CH3CHO +4NaOH +3I2 ------ CHI3
+ HCOONa +3H2O +3NaI
Formaldeyhyde does not give this test.
4)Acetaldehyde and Acetone
Acetaldehyde gives silver mirror with Tollen;s reagent
CH3CHO + 2[Ag(NH3)2OH ----- CH3COONH4 + 2Ag +H2O +3NH3
Acetone does not give this test
Acetaldehyde gives red ppt with Fehling solutions
CH3CHO + 2Cu(OH)2 +2NaOH --------- CH3COONa +Cu2O +3H2O
[Fehling solution]
Red ppt.
5)Benzaldehyde and Acetophenone
 Benzaldehyde forms silver with ammonical silver nitrate
solution(Tollen;s reagent)
 Acetophenone does not
 C6H5CHO + 2[Ag (NH3)2OH -----C6H5COONH4 + 2Ag
3NH3 +H2O
 Acetophenone forms yellow ppt of iodoforrm with alkaline
solution of iodine.
 Benzaldehyde does not.
 C6H5COCH3 +4NaOH + 3I2 --C6H5COONa + CHI3 + 3NaI
6)DIFFERENCE BETWEEN FORMIC ACID AND ACETIC ACID
 Formic acid give Tollen;s reagent test.
 HCOOH + 2 [Ag(NH3)2]+ + 2 OH- → 2 Ag + CO2 + 2H2O + 4 NH3
 Acetic acid does not give this test
7) Acetic acid and Acetone
Acetic acid reacts with NaHCO3 To give effervescence due to
evoltion of CO2
 CH3COOH + NaHCO3 --- CH3COONa + H2O + CO2
 Acetone does not give effervescence with NaHCO3
 Acetone will react with alkaline solution of iodine to give yellow
ppt due to formation of iodoform.
 CH3COCH3
+ NaOI
---CHI3
+
CH3COONa .
8)Phenol and Benzoic acid
Benzoic acid react with NaHCO3 to give effervescence due to
evolution of CO2.
C6H5COOH + NaHCO3 ---- C6H5COONa + H20 + CO2 .
Phenol does not give this test .
Phenol will give violet colour with .FeCl3 solution but Benzoic acid
does not give this test.
3C6H5COOH + FeCl3 ----- (C6H5O)3Fe + 3HCl.
9)Phenol and Acetic acidAcetic react with NaHCO3 to give
effervescence due to evolution of CO2
 CH3COOH + NaHCO3
------ CH3COONa + CO2 + H2O
 Phenol does not give this test
 C6H5COOH + NaHCO3 ---- No reaction
 Phenol gives violet colour with FeCl3 but acetic acid gives buff
coloured ppt.
 3C6H5OH + FeCl3 --(C6H5O)3 + 3HCl
 3CH3COOH + FeCl3 ---.. (CH3COO)3 Fe + 3HCl
Buff ppt
Prepared by Jayashree S
PGT CHEMISTRY KV CLRI