Postlab - Carbo (Qualitative Tests) Flashcards
Test for reducing sugars
Benedict’s Test
Test that is sensitive than Fehling’s Test
Benedict’s Test
Reagents used in Benedict’s Test
CuSO₄
Na₂CO₃
Na₃C₆H₅O₇
Test where:
Cu²⁺ oxidizing agent (OXIDATION)
Benedeict’s test
Barfoed’s Test
Test where principle is:
Cupric ions reduced to cuprous, form Cu₂O precipitate
Benedict’s Test
Barfoed’s Test
Test where Principle is:
Sodium citrate (BASIC) used to keep Cu ions in solution
Benedict’s Test
What color of the precipitate for all reducing sacchardies in benedict’s test
Brick-Red
What test has the “Brick-red” precipitate for all reducing saccharides
Benedict’s Test
Test that refers to:
All monosaccharides are reducing saccharides
Benedict’s test
What test is this?
Glucose ——Blue——> Gluconic Acid
Benedict’s test
WHat test distinguishes reducing monosaccharides & disaccharides
(mono- forms Cu₂O faster than di- in acidic medium)
Barfoed’s test
Reagents used are Cu(CH₃COO)₂, acetic acid. What test is it?
Barfoed’s Test
Test result of Barfoed’s Test in monosaccharide
Brick-red in less than 3 minutes
Test result of Barfoed’s Test in disaccharide
Brick-red for around 10 minutes
(considered as a negative result)
What test uses these reagents
HCl, FeCl₃ and orcinol
Bial’s Orcinol Test
What test involved this principle?
Strong acid to dehydrate monosaccharide
to produce furfural or hydroxymethylfurfural
Bial’s Orcinol Test
What test will then condense with orcino?
Bial’s Orcinol Test
Visual Positive result of Bbial’s Orcinol Test
Blue-green solution for aldopentoses
Test specfici for galactose and lactose
Mucic Acid Test
True of False
In Mucic Acid Test:
- formyl functional group will get oxidized to carboxylic acid
- Primary alcohol group will get oxidized to carboxylic acid
True
What test is this associated?
BROKEN GLASS- LIKE/RHOMBIC CRYSTALS
Mucic Acid Test
Mucic Acid Test is Plane of symmetry – not optically active
T or F
True
Test for all sugars w/ free carbonyl group at C1 or C2
Phenylhydrazone or Osazone Test
Test where reagent used is phenylhydrazine
Phenylhydrazone/Osozone Test
