org tests

Question 1

What is the Tollen’s test used to detect?

Answer 1

Aldehydes (gives a silver mirror with aldehydes)

Question 2

What is the observation in Tollen’s test with an aldehyde?

Answer 2

Formation of a silver mirror on the test tube wall

Question 3

What compound does not respond to Tollen’s test?

Answer 3

Ketones (except alpha-hydroxy ketones)

Question 4

What is Fehling’s solution test used for?

Answer 4

Detection of aliphatic aldehydes

Question 5

What is observed in Fehling’s test with aliphatic aldehydes?

Answer 5

Formation of a reddish-brown precipitate of Cu₂O

Question 6

Why don’t aromatic aldehydes give Fehling’s test?

Answer 6

Because they are not strong reducing agents

Question 7

What is the iodoform test used to detect?

Answer 7

Compounds with CH₃CO– group or CH₃CH(OH)– group (e.g., ethanol, acetone)

Question 8

What is the positive observation for the iodoform test?

Answer 8

Formation of a yellow precipitate of iodoform with a characteristic smell

Question 9

Which types of alcohols give a positive iodoform test?

Answer 9

Methyl ketones and ethanol or alcohols oxidizable to methyl ketones

Question 10

What is Lucas test used for?

Answer 10

Differentiating primary, secondary, and tertiary alcohols

Question 11

What is the reagent used in the Lucas test?

Answer 11

Lucas reagent (ZnCl₂ + conc. HCl)

Question 12

What is the observation for tertiary alcohols in Lucas test?

Answer 12

Immediate turbidity

Question 13

What is the observation for secondary alcohols in Lucas test?

Answer 13

Turbidity appears in 5–10 minutes

Question 14

What is the observation for primary alcohols in Lucas test?

Answer 14

No turbidity at room temperature

Question 15

What is the bromine water test used for?

Answer 15

Detecting unsaturation (C=C double bonds)

Question 16

What is the positive observation in bromine water test?

Answer 16

Decolorization of reddish-brown bromine water

Question 17

What is the Baeyer’s test?

Answer 17

Test for unsaturation using cold dilute alkaline KMnO₄

Question 18

What is the observation in Baeyer’s test?

Answer 18

Purple color of KMnO₄ disappears, and brown precipitate of MnO₂ may form

Question 19

What is the carbylamine test used to detect?

Answer 19

Primary amines

Question 20

What is the reagent used in the carbylamine test?

Answer 20

Chloroform + alcoholic KOH

Question 21

What is the positive observation in the carbylamine test?

Answer 21

Foul-smelling isocyanide is formed

Question 22

What is the Hinsberg test used for?

Answer 22

Distinguishing 1°, 2°, and 3° amines

Question 23

What reagent is used in Hinsberg test?

Answer 23

Benzenesulfonyl chloride in NaOH

Question 24

What is the result of Hinsberg test for primary amines?

Answer 24

Forms a sulfonamide soluble in alkali

Question 25

What is the result of Hinsberg test for secondary amines?

Answer 25

Forms a sulfonamide insoluble in alkali

Question 26

What is the result of Hinsberg test for tertiary amines?

Answer 26

No reaction

Question 27

What is the sodium metal test used for?

Answer 27

Detection of alcohols

Question 28

What is the positive observation in sodium metal test?

Answer 28

Effervescence due to hydrogen gas evolution

Question 29

What is the Ceric Ammonium Nitrate (CAN) test used for?

Answer 29

Detection of alcohols

Question 30

What is the observation in CAN test with alcohols?

Answer 30

Red color appears

Question 31

What is the ferric chloride test used for?

Answer 31

Detection of phenols

Question 32

What is the observation in ferric chloride test with phenols?

Answer 32

Violet, blue, green or red coloration

Question 33

What is the sodium bicarbonate test used for?

Answer 33

Detection of carboxylic acids

Question 34

What is the observation in sodium bicarbonate test?

Answer 34

Brisk effervescence due to CO₂ gas

Question 35

What is the bromine in CCl4 test used for?

Answer 35

Detection of unsaturation (C=C)

Question 36

What is the observation in bromine in CCl4 test?

Answer 36

Decolorization of reddish bromine in CCl4

Question 37

What is the nitroprusside test used for?

Answer 37

Detection of methyl ketones

Question 38

What is the observation in nitroprusside test?

Answer 38

Red color due to formation of complex

Question 39

What happens when methyl ketone is treated with sodium nitroprusside and base?

Answer 39

Reddish-violet color is produced

Question 40

What is the Leuco test used for?

Answer 40

Detection of aromatic primary amines

Question 41

What is the observation in Leuco test?

Answer 41

Formation of colored dye with leuco reagent

Question 42

What is the dye test used for?

Answer 42

Detection of aromatic primary amines

Question 43

What is the positive observation in dye test?

Answer 43

Formation of azo dye (orange-red)

Question 44

How can you test for aniline?

Answer 44

Diazotization followed by coupling with β-naphthol to form an azo dye

Question 45

What is Lassaigne’s test used for?

Answer 45

Detection of extra elements (N, S, halogens) in organic compounds

Question 46

What is the test for nitrogen in Lassaigne’s extract?

Answer 46

Formation of Prussian blue with ferrous sulfate and NaOH

Question 47

What is the test for sulphur in Lassaigne’s extract?

Answer 47

Formation of black precipitate of PbS with lead acetate

Question 48

What is the test for halogens in Lassaigne’s extract?

Answer 48

Precipitate with AgNO₃ after acidifying with HNO₃

Question 49

What is the Beilstein test used for?

Answer 49

Detection of halogens

Question 50

What is the observation in Beilstein test?

Answer 50

Green flame due to copper halide formation

Question 51

What is the Tafel test used for?

Answer 51

Detection of nitro compounds

Question 52

What is the observation in Tafel test?

Answer 52

Red or violet coloration

Question 53

What is the acylation test used for?

Answer 53

Detection of alcohols and amines

Question 54

What is the reaction in acylation test?

Answer 54

Alcohols and amines react with acid chlorides or anhydrides to form esters/amides

Question 55

What is the phthalein test used for?

Answer 55

Detection of phenols

Question 56

What is the observation in phthalein test?

Answer 56

Pink or red color in presence of phenol and phthalic anhydride with conc. H₂SO₄

Question 57

What is the Liebermann’s test used for?

Answer 57

Detection of phenol

Question 58

What is the observation in Liebermann’s test?

Answer 58

Green or blue coloration on adding NaNO₂ and conc. H₂SO₄