QUALITATIVE ANALYSIS Flashcards
not enough still do the tests using other decks..
How can transition metal ions be identified
NaOH (aq) forms coloured precipitates with transition metal ions
How do you test for carbonate ions
Add acid e.g. HCl
Produces CO2 gas (effervesence)
Bubble through lime water and it will turn cloudy
How do you test for Sulfate ions
Add acidified BaCl2
white precipitate (BaSO4)
How do you test for Halides
Add Nitric acid
Add SilverNitrate
precipitates form : Cl-white,Br-cream,I-pale yellow
What do you do if halide test colours are unclear
Add ammonia and check solubility:
Silver chloride dissolves in dilute ammonia to form a complex ion
Silver bromide dissolves in concentrated ammonia
Silver iodide does not react with ammonia – it is too insoluble.
How do you test for alkenes
Bromine water
Orange colour decolourises
How do you test for carbonyls
2,4-DNP
Orange precipitate forms
How do you test for aldehyde
Tollen’s reagent
Silver mirror formed
How do you test for carboxylic acids
carbonate ions e.g. in Na2CO3
Effervesence of CO2
could bubble in limewater to check (goes cloudy)
How to test for primary or secondary alcohol/ alehyde
Add potassiumdichromate/sodiumdichromate
and sulfuric acid (to acidify)
ORANGE TO GREEN
How to test for Haloalkane
warm with aqueous silver nitrate in ethanol
Slow formation of white precipitate
How to test for Phenols
add Sodium or Sodium Hydroxide (NaOH)
Fizzing
(no fizzing with SociumCarbonate)
