Identification of functional groups Flashcards
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What groups are soluble in water/ have one layer?
Small carbon chains (1-5), alcohols, amides, aldehydes & ketones, carboxylic acids and small esters
What groups are insoluble in water/ make 2 layers?
Large alcohols, amines, carboxylic acids, amides and esters and ALL alkanes, alkynes and haloalkanes
What turns moist red litmus paper blue?
Amines
What turn moist blue litmus paper reds?
Carboxylic acids
What turns UI solution from green to blue
Amines
What turns UI solution from green to orange
Carboxylic acid
What turns Cr2O7^2-/H+ (aq) to Cr^3+ (aq) changing orange to green when heated
Primary alcohols, secondary alcohols and aldehydes
What turns Mno4-/H+ (aq) to Mn^2+ (aq), changing purple to colourless
Primary alcohols, secondary alcohols and aldehydes
What turns Mno4-/H+ (aq) to Mn^2+ (aq), changing purple to colourless
Alkenes
What turns Mno4-/H+ (aq) to MnO2 , changing purple to brown precipitate
Alkenes
Reacts with NAHCO3 or NA2CO3 solid or solution to produce colourless gas CO2
Carboxylic acid
Reacts with Mg (or other reactive metals) to produce colourless gas H2
Carboxylic acid
Has a fishy smell
Amines
Have a ‘sharp’ or vinegary smell
Carboxylic acids
Rapidly decolourise orange bromine water, Br2
Alkenes and alkynes (unsaturated)
Slowly decolourise orange bromine water, Br2 needing UV light and heat
Alkanes/other molecules with C-C bonds (saturated)
Usually have a pleasant fruity smell
Esters
React vigorously with water, and make HCl fumes
Acyl chloride
React with blue Cu^2+ (aq) to form deep blue solution
Amines
Give a silver mirror (black ppt) with Tollens’s reagent
Aldehydes
Give a red/ orange precipitate of Cu2O with Benedict’s or Fehling’s reagent (Cu^2+)
Aldehydes
Able to rotate plane polarised light
Molecules with asymmetrical C atom
Soluble in water- one layer
Polar molecule
Insoluble in water- two layers
Non-polar molecule
Release NH3 gas if heated with NaOH, turns red litmus blue
Amides
