MolSynapse / Question bank / Structural Identification and Practical Organic Chemistry / Distinguishing tests for functional groups

Distinguishing tests for functional groups

55 questions on Distinguishing tests for functional groups from the Structural Identification and Practical Organic Chemistry chapter: 11 NEET level, 22 JEE Main, 22 JEE Advanced. Each one opens with its answer and solution.

Practice this topic All Structural Identification and Practical Organic Chemistry topics

In Victor Meyer's test, propan-2-ol is converted successively to the alkyl iodide (red P/I2), the nitroalkane (AgNO2), then treated with HNO2 and finally made a... JEE Main level
But-1-yne and but-2-yne can be distinguished by JEE Main level
Ethyl bromide is warmed with aqueous NaOH, the solution is acidified with dilute HNO3 and AgNO3 solution is added. The observation is NEET level
In a Kjeldahl estimation, 0.750 g of an organic compound was digested and the ammonia evolved was absorbed in 40.0 mL of 0.500 M H2SO4. The excess acid required... JEE Advanced level
Which of the following pairs can be distinguished by the single reagent indicated? (more than one may be correct) JEE Advanced level
Butan-2-ol and 2-methylpropan-2-ol can be distinguished by JEE Main level
Assertion (A): Benzoic acid gives brisk effervescence with aqueous NaHCO3, whereas phenol does not. Reason (R): Phenol is a stronger acid than carbonic acid. Ch... JEE Advanced level
Consider the sequence C6H5NO2 xrightarrowSn/HCl A xrightarrowNaNO2/HCl, 273-278 K B xrightarrowCuCN C xrightarrowH3O+, heat D. Which set of observations is corr... JEE Advanced level
Which of the following decolourise cold, dilute, alkaline KMnO4 (Baeyer's reagent)? (more than one may be correct) JEE Advanced level
A hydrocarbon A (C5H8) decolourises Br2/CCl4 and gives a white precipitate with ammoniacal AgNO3. Complete catalytic hydrogenation of A gives 2-methylbutane. A ... JEE Advanced level
Which statements about the action of NaNO2/HCl on amines are correct? (more than one may be correct) JEE Advanced level
Which of the following does NOT form a crystalline addition product with saturated aqueous NaHSO3? JEE Main level
A compound C8H8O2 is neutral to litmus, gives no effervescence with NaHCO3 and no colour with neutral FeCl3. Boiling with aqueous NaOH and then acidifying gives... JEE Advanced level
The degree of unsaturation (double bond equivalents) of 4-nitrobenzoyl chloride, O2N-C6H4-COCl (molecular formula C7H4ClNO3), is to be calculated using the form... JEE Main level
Which of the following reagents can be used to distinguish propanal from propanone? (more than one may be correct) JEE Main level
A student adds benzenesulphonyl chloride to excess aqueous KOH and then the amine. For which amines does the mixture give a clear alkaline solution (soluble sul... JEE Main level
Which compound, after treatment with NaNO2/HCl at 273-278 K and then with alkaline 2-naphthol, gives an orange-red dye? JEE Main level
A solid on boiling with aqueous NaOH liberates a gas that turns moist red litmus blue. Acidifying the residual solution gives a white precipitate. The solid is JEE Main level
Pentan-2-one and pentan-3-one can be distinguished by JEE Main level
A neutral fruity-smelling liquid C4H8O2 gives no effervescence with NaHCO3, no hydrogen with sodium and no silver mirror. On boiling with aqueous NaOH it gives ... JEE Main level
Which halide gives a white precipitate fastest with alcoholic AgNO3 at room temperature? JEE Main level
Which hydrocarbon gives a white precipitate with ammoniacal silver nitrate? NEET level
Which of the following gives brisk effervescence of CO2 with aqueous sodium hydrogencarbonate? NEET level
Which compound restores the pink colour of Schiff's reagent but does not reduce Fehling's solution? JEE Main level
The correct order of speed of turbidity formation (fastest to slowest) with Lucas reagent at room temperature is JEE Main level
A compound C8H8O gives an orange precipitate with 2,4-DNP and a yellow precipitate with NaOH/I2, is negative with Tollens and Fehling, and gives benzoic acid on... JEE Advanced level
A purple ring at the junction of two layers on adding alpha-naphthol and concentrated H2SO4 (Molisch test) is given by NEET level
Which compound gives a red precipitate of Cu2O on warming with Fehling's solution? NEET level
Phenol and benzoic acid can be distinguished by using JEE Main level
Three isomeric amines of formula C3H9N are P, Q and R. P gives a foul-smelling isocyanide with CHCl3/alcoholic KOH; Q reacts with benzenesulphonyl chloride to g... JEE Advanced level
Ethanal is treated with dilute NaOH at room temperature to give the aldol P, which on heating gives Q. Which single reagent distinguishes P from Q? JEE Advanced level
Which reagent can be used to distinguish ethanal from propanone? NEET level
A liquid X (C8H11N) gives no foul-smelling compound on warming with CHCl3 and alcoholic KOH. When shaken with benzenesulphonyl chloride and aqueous KOH it is re... JEE Advanced level
Which alcohol gives turbidity immediately at room temperature with Lucas reagent (ZnCl2/conc. HCl)? NEET level
Compound A (C7H6O) gives a silver mirror with Tollens reagent but no precipitate with Fehling's solution. A is shaken with concentrated aqueous NaOH and the mix... JEE Advanced level
A compound C4H8O gives an orange precipitate with 2,4-DNP, no silver mirror with Tollens reagent, and a yellow precipitate with NaOH/I2. It is JEE Main level
An isomer of C7H8O gives violet colour with neutral FeCl3, and with excess bromine water it gives a white precipitate in which three hydrogen atoms of the ring ... JEE Advanced level
Which of the following give a violet or blue colouration with neutral FeCl3? (more than one may be correct) JEE Main level
Sucrose gives a negative result with Benedict's solution, but gives a positive result when it is first boiled with dilute HCl and then neutralised. The reason i... JEE Main level
When phenol is treated with excess bromine water, the product that separates as a white precipitate is NEET level
In Lassaigne's test, the sodium extract of an organic compound containing nitrogen (but no sulphur) is boiled with FeSO4 and then acidified with concentrated H2... NEET level
The carbylamine (isocyanide) test with CHCl3 and alcoholic KOH on warming is positive for NEET level
Which reagents can be used to distinguish benzaldehyde from acetophenone? (more than one may be correct) JEE Advanced level
The single reagent that distinguishes methanal from ethanal is JEE Main level
Which of the following give a yellow precipitate of CHI3 with NaOH/I2? (more than one may be correct) JEE Main level
Which of the following gives a violet colouration with neutral FeCl3? NEET level
An alcohol X (C4H10O) becomes turbid with Lucas reagent at room temperature only after about five minutes and gives a yellow precipitate with NaOH/I2. The sodiu... JEE Advanced level
A compound X (C7H7Cl) is boiled with aqueous NaOH, acidified with dilute HNO3 and treated with AgNO3: no precipitate forms. Oxidation of X with hot alkaline KMn... JEE Advanced level
Which of the following give effervescence of CO2 with aqueous NaHCO3? (more than one may be correct) JEE Advanced level
Match the observation in List I with the compound in List II. List I: (P) silver mirror with Tollens reagent and no yellow precipitate with NaOH/I2; (Q) yellow ... JEE Advanced level
Which statements about Lassaigne's test and the sodium extract are correct? (more than one may be correct) JEE Advanced level
Nitrobenzene is warmed with Zn dust and NH4Cl solution, filtered, and the filtrate is treated with Tollens reagent. A grey-black precipitate of silver forms bec... JEE Main level
Which of the following substances reduce warm Tollens reagent to give a silver mirror? (more than one may be correct) JEE Advanced level
An amine C7H9N gives a sulphonamide with benzenesulphonyl chloride that is insoluble in aqueous KOH, and gives a yellow oily compound with NaNO2/HCl. The amine ... JEE Main level
Aqueous solutions of glucose and fructose are to be distinguished. Which reagent works? JEE Advanced level