FINAL 02 - Qualitative Tests for Carbohydrates Flashcards
Molisch’s test (Test for)
General test for carbohydrates
Molisch’s test (Composition)
α-Naphthol
Molisch’s test (Positive result)
Purple/red ring
Molisch’s test (Principle)
Dehydration
Molisch’s test produces a derivative of furfural known as __________
5-hydroxymethylfurfural
Fehling’s test (Test for)
Reducing sugars
Fehling’s test A (Composition)
CuSO4.5H2O (Copper sulfate pentahydrate)
Fehling’s test B (Composition)
K Na Tartrate
Fehling’s test (Positive result)
Brick red ppt
Fehling’s test (Principle)
Reduction
Benedict’s test (Test for)
Reducing sugars
In Benedict’s test, __________ provides the alkaline conditions which are required for the redox reaction
Sodium carbonate
In Benedict’s test, __________ complexes with the copper (II) ions so that they do not deteriorate to copper (I) ions during storage
Sodium citrate
Benedict’s test (Composition)
NaOH + CuSO4
Benedict’s test (Positive resut)
Brick red ppt
Benedict’s test (Principle)
Reduction
Barfoed’s test (Test for)
Monosaccharides
In Barfoed’s test, monosaccharides usually react in about __________ to __________ minutes
1-2 minutes
In Barfoed’s test, disaccharides take a much longer time to react with the reagent, about __________ to ___________ minutes
7-12 minutes
Barfoed’s test (Composition)
Cupric acetate + Acetic acid
Barfoed’s test (Positive result)
Brick red ppt
Barfoed’s test (Principle)
Reduction
Tollen’s test (Test for)
Aldehydes
Tollen’s test (Composition)
Silver + Ammonia
Tollen’s test (Positive result)
Silver mirror
Tollen’s test (Principle)
Redox
Picric acid test (Test for)
Reducing sugars
Picric acid test (Composition)
Picric acid
Picric acid test (Positive result)
Mahogany red
Picric acid test (Principle)
Reduction
In picric acid test, the reducing sugars react with picric acid, also chemically known as __________, to form red colored picramic acid
2,4,6-trinitrophenol (TNP)
In picric acid test, the reducing sugars react with picric acid, also chemically known as 2,4,6-trinitrophenol (TNP), to form red colored __________
Picramic acid
Nylander’s test (Test for)
Reducing sugars
Nylander’s test (Composition)
Na K tartrate + K/NaOH + Bi
Nylander’s test (Positive result)
Brown
Nylander’s test (Principle)
Reduction
Osazone/Kowarsky test (Test for)
Mannose
Osazone/Kowarsky test (Composition)
Phenylhydrazine
Osazone/Kowarsky test (Positive result)
Yellow ppt
Osazone/Kowarsky test (Principle)
Reduction
Seliwanoff’s test (Test for)
Ketones/Ketohexoses (Fructose)
Seliwanoff’s test (Composition)
Resorcinol in conc. HCl
Seliwanoff’s test (Positive result)
Red/Pink
Seliwanoff’s test (Principle)
Dehydration
Keller-Killiani test (Test for)
Deoxysugars (Cardiac glycosides)
Keller-Killiani test (Composition)
Acetic acid, Fe chloride, Sulfuric acid
Keller-Killiani test (Positive result)
Reddish brown
Keller-Killiani test (Principle)
Hydrolysis
Mucic acid test (Test for)
Galactose
Mucic acid test (Composition)
Nitric acid
Mucic acid test (Positive result)
Insoluble ppt
Mucic acid test (Principle)
Oxidation
Moore’s test (Test for)
Glucose
Moore’s test (Composition)
Heat with alkali
Moore’s test (Positive result)
Caramel
Bial’s test (Test for)
Pentoses
Bial’s test (Composition)
Resorcinol + Fe
Bial’s test (Positive result)
Blue green
Bial’s test (Principle)
Dehydration