Organic Chemistry Describe the qualitative tests that could be used to distingui

Question

Organic Chemistry Describe the qualitative tests that could be used to distinguish between the following pairs of compounds. Describe what you would do and what you would see.

anilineand benzyl alcohol

aniline and phenol – two tests

aniline and benzylamine

aniline and p-aminophenol –two tests

aniline and benzamide

aniline and N-methyl aniline – two tests

Acetyl chloride: A test for alcohols and primary/secondary amines - (+) test: an exothermic reaction(eruption) Possible false positive: some phenols(?) A test for halogenated compounds (+ Beilstein test: ) test: green flame Possible false positive: some non-halogenated amines A test for carboxylic acids A test for alkenes and alkynes-Ral-colorless (+) test: discharge of bromine red color co date K-aat- A test for activated phenols and anilines (+) test: formation of a white ppt A test for alcohols (+) test: formation of a blood red color Possible false positive: some amines and phenols Bicarbonate: (+) test: fizzing Br2/H2O: Ceric nitrate: A test for aldehydes and primary /secondary ROH (+) test: dark red to green within two minutes Possible false positive: some anilines and phenols Chromic anhydride: A test for aldehydes/ketones (+) test: formation of a red, orange, or yellow ppt Possible false positive: some amines A test for phenols (+) test: 2,4-DNPH: Ferric chloride: formation of a violet, purple, blue, green, or red- brown color Possible false positive: amines and alcohols A test to differentiate between tertiary water-soluble alcohols and secondary/primary water-soluble alcohols (+) test: Formation of an insoluble layer within two Lucas test: minutes for tertiary water-soluble alcohol Iodoform test: A test for methyl carbinols and methyl ketones (ethanal) (+ ) test: Formation of a yellow-orange ppt A test to differentiate between primary, secondary, and tertiary amines Primary alkyl amines: bubbling (N2 gas); no red-orange Nitrous acid: Primary aryl amines: Secondary amines Tertiary amines: ppt with -naphthol no bubbling; red-orange ppt with -naphthol formation of yellow oil/ppt of (carcinogenic?) nitrosamine dissolve in acidic medium; no observable reaction A test for aldehydes (+) test: Formation of a silver mirror Possible false positive: some anilines and phenols Tollens test:

Explanation / Answer

Aniline and benzyl alcohol:

1.Odour: The odour of benzyl alcohol is faint pleasant whereas of aniline is that of rotten eggs.

2.Ceric ammonium nitrate reagent: Ceric ammonium nitrate (yellow solution) is an oxidizing agent that reacts with alcohols to give a red complex. In this we mix two drops of the alcohol with 0.5 ml dioxane, shake well, and add one drop of the reagent to get a positive red complex.

aniline and phenol – two tests

1.Water solubility: Aniline is insoluble in water, whereas phenol is sparingly soluble in water.

2.Litmus test – Aniline is basic in nature, hence turns red litmus blue. However phenol being slightly acidic, it turns blue litmus red.

aniline and benzylamine:

aniline and p-aminophenol –two tests

1.P-aminophenol is a solid and hence can be recrystallized from hot water, whereas aniline cannot be recrystallized.

2.Anline gives the azodye test, p-aminophenol does not.

aniline and benzamide

aniline and N-methyl aniline – two tests

2.Aniline and N-methylaniline can be tested using the azodye test. We heat the respective amines with NaNO2 and HCl which is followed by treatment with an alkaline solution of 2-naphthol. This gives a brilliant orange, yellow ar red dye. The formation of this azodye is seen only with aniline. N-Methylaniline does not give this azodye test. Instead it gives a yellow colored oil.

Related Questions

Navigate

• Browse (All)
• Browse O
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.