Identifications Flashcards
(17 cards)
How to identify Phenol
(2 answers)
1) Br₂ - forms white precipitate
2) FeCl₃ - forms purple coloured complex
How to identify Amines
Damp red litmus paper turns blue
How to identify Amides
NaOH (hydrolysis) then red litmus paper turns blue
How to identify Carboxylic Acids
(2 answers)
1) Soda lime - colourless gas evolves
2) NaHCO₃ or Na₂CO₃ - gas evolves
How to identify Alcohols
H⁺/Cr₂O₇²⁻ reflux - orange to green
How to identify Carbonyls
(4 answers)
1) 2-4 DNPH (both A&K) - orange crystals
2) Tollens (A) - silver mirror
3) Fehling’s, strong heat (A) - Brick red
4) Iodoform (Methyl K) - yellow precipitate
Chloride ions
NaOH, then HNO₃ and AgNO₃, then NH₃
White precipitate forms (AgCl) which redissolves in dilute NH₃
Bromide ions
NaOH, then HNO₃ and AgNO₃, then NH₃
Cream precipitate forms (AgBr) which redissolves in excess NH₃
Iodide ions
NaOH, then HNO₃ and AgNO₃, then NH₃
Yellow precipitate forms (AgI) which doesn’t redissolve in NH₃
Add aqueous Pb²⁺
Bright/canary yellow precipitate
Sulfate ions
HCl then BaCl₂
White precipitate (BaSO₄)
Lithium ions
Flame test
Red
Sodium ions
Flame test
Yellow
Potassium ions
Flame test
Lilac
Calcium ions
Flame test
Brick red
Strontium ions
Flame test
Crimson
Barium ions
Flame test
Apple green
Copper ions
Flame test
Green-blue
