Saved Bookmarks
| 1. |
State chemical tests to distinguish between the following pairs of compounds: (i) Propanal ad propanone. (ii) Phenol and bennzoic acid. |
|
Answer» Solution :(i) Propanal and propanone: The two componds can be distinguished by iodoform TEST. Propanone contains `CH_(3)CO`- group and gives iodoform test while propanal `(CH_(3)CH_(2)CHO)` does not give iodoform test. `CH_(3)COCH_(3)+3NaOItoCH_(3)COONa+2NaoH+underset("Iodoform")(CHI_(3))` (ii) Phenol and benzoic acid: The two compounds can be distinguished as under: Ferric chloride test: Phenol gives a violet colour with aqueous `FeCl_(3)` while benzoic acid gives buff coloured ppt. of ferric benzoate. < br> `underset("Phenol")(C_(6)H_(5)OH)+FeCl_(3)to` violet colour `underset("Benzoic acid")(3C_(6)H_(5)COOH)+FeCl_(3)tounderset(("Buff coloured ppt"))underset(Ferric benzoate")((C_(6)H_(6)COO)_(3)Fe+3HCl` Sodium BICARBONATE test: Phenol is a weaker acid than benzoic acid. While benzoic acid DECOMPOSES sodium bicarbonate, phenol does not. `C_(6)H_(5)COOH+NaHCO_(3)toC_(6)H_(5)COONa+CO_(2)uarr+H_(2)O` `C_(6)H_(5)OH+NaHCO_(3)to` No action. |
|