FINAL 02 - Qualitative Tests for Carbohydrates

Question 1

Molisch’s test (Test for)

Answer 1

General test for carbohydrates

Question 2

Molisch’s test (Composition)

Answer 2

α-Naphthol

Question 3

Molisch’s test (Positive result)

Answer 3

Purple/red ring

Question 4

Molisch’s test (Principle)

Answer 4

Dehydration

Question 5

Molisch’s test produces a derivative of furfural known as __________

Answer 5

5-hydroxymethylfurfural

Question 6

Fehling’s test (Test for)

Answer 6

Reducing sugars

Question 7

Fehling’s test A (Composition)

Answer 7

CuSO4.5H2O (Copper sulfate pentahydrate)

Question 8

Fehling’s test B (Composition)

Answer 8

K Na Tartrate

Question 9

Fehling’s test (Positive result)

Answer 9

Brick red ppt

Question 10

Fehling’s test (Principle)

Answer 10

Reduction

Question 11

Benedict’s test (Test for)

Answer 11

Reducing sugars

Question 12

In Benedict’s test, __________ provides the alkaline conditions which are required for the redox reaction

Answer 12

Sodium carbonate

Question 13

In Benedict’s test, __________ complexes with the copper (II) ions so that they do not deteriorate to copper (I) ions during storage

Answer 13

Sodium citrate

Question 14

Benedict’s test (Composition)

Answer 14

NaOH + CuSO4

Question 15

Benedict’s test (Positive resut)

Answer 15

Brick red ppt

Question 16

Benedict’s test (Principle)

Answer 16

Reduction

Question 17

Barfoed’s test (Test for)

Answer 17

Monosaccharides

Question 18

In Barfoed’s test, monosaccharides usually react in about __________ to __________ minutes

Answer 18

1-2 minutes

Question 19

In Barfoed’s test, disaccharides take a much longer time to react with the reagent, about __________ to ___________ minutes

Answer 19

7-12 minutes

Question 20

Barfoed’s test (Composition)

Answer 20

Cupric acetate + Acetic acid

Question 21

Barfoed’s test (Positive result)

Answer 21

Brick red ppt

Question 22

Barfoed’s test (Principle)

Answer 22

Reduction

Question 23

Tollen’s test (Test for)

Answer 23

Aldehydes

Question 24

Tollen’s test (Composition)

Answer 24

Silver + Ammonia

Question 25

Tollen's test (Positive result)

Answer 25

Silver mirror

Question 26

Tollen's test (Principle)

Answer 26

Redox

Question 27

Picric acid test (Test for)

Answer 27

Reducing sugars

Question 28

Picric acid test (Composition)

Answer 28

Picric acid

Question 29

Picric acid test (Positive result)

Answer 29

Mahogany red

Question 30

Picric acid test (Principle)

Answer 30

Reduction

Question 31

In picric acid test, the reducing sugars react with picric acid, also chemically known as __________, to form red colored picramic acid

Answer 31

2,4,6-trinitrophenol (TNP)

Question 32

In picric acid test, the reducing sugars react with picric acid, also chemically known as 2,4,6-trinitrophenol (TNP), to form red colored __________

Answer 32

Picramic acid

Question 33

Nylander's test (Test for)

Answer 33

Reducing sugars

Question 34

Nylander's test (Composition)

Answer 34

Na K tartrate + K/NaOH + Bi

Question 35

Nylander's test (Positive result)

Answer 35

Brown

Question 36

Nylander's test (Principle)

Answer 36

Reduction

Question 37

Osazone/Kowarsky test (Test for)

Answer 37

Mannose

Question 38

Osazone/Kowarsky test (Composition)

Answer 38

Phenylhydrazine

Question 39

Osazone/Kowarsky test (Positive result)

Answer 39

Yellow ppt

Question 40

Osazone/Kowarsky test (Principle)

Answer 40

Reduction

Question 41

Seliwanoff's test (Test for)

Answer 41

Ketones/Ketohexoses (Fructose)

Question 42

Seliwanoff's test (Composition)

Answer 42

Resorcinol in conc. HCl

Question 43

Seliwanoff's test (Positive result)

Answer 43

Red/Pink

Question 44

Seliwanoff's test (Principle)

Answer 44

Dehydration

Question 45

Keller-Killiani test (Test for)

Answer 45

Deoxysugars (Cardiac glycosides)

Question 46

Keller-Killiani test (Composition)

Answer 46

Acetic acid, Fe chloride, Sulfuric acid

Question 47

Keller-Killiani test (Positive result)

Answer 47

Reddish brown

Question 48

Keller-Killiani test (Principle)

Answer 48

Hydrolysis

Question 49

Mucic acid test (Test for)

Answer 49

Galactose

Question 50

Mucic acid test (Composition)

Answer 50

Nitric acid

Question 51

Mucic acid test (Positive result)

Answer 51

Insoluble ppt

Question 52

Mucic acid test (Principle)

Answer 52

Oxidation

Question 53

Moore's test (Test for)

Answer 53

Glucose

Question 54

Moore's test (Composition)

Answer 54

Heat with alkali

Question 55

Moore's test (Positive result)

Answer 55

Caramel

Question 56

Bial's test (Test for)

Answer 56

Pentoses

Question 57

Bial's test (Composition)

Answer 57

Resorcinol + Fe

Question 58

Bial's test (Positive result)

Answer 58

Blue green

Question 59

Bial's test (Principle)

Answer 59

Dehydration