Identification tests Flashcards
What substance can be used to differentiate soluble and insoluble organic substances, and how?
Water - non-polar substances will be immiscible and form 2 layers with the water, polar substances will mix so there will only be 1 layer
What organic molecules are soluble in water?
Alcohols, carboxylic acids, amines
What organic molecules are insoluble in water?
Alkanes, alkenes, alkynes, haloalkanes, long chain alcohols, carboxylic acids & amines
How can alkanes and alkenes be differentiated?
Addition of Br2 - alkenes rapidly react and decolourise the brown colour to colourless, alkanes slowly react and decoolourise the bromine under the prescense of UV light
What is the test for a primary alcohol?
Addition of acidified dichromate - oxidation reaction will occur to form a carboxylic acid and the dichromate will turn from orange to green
How can carboxylic acids and amines be differentiated?
Carboxylic acids and acidic so will turn blue litmus red, amines are basic and will turn red litmus blue
Is an alcohol acidic, basic or neutral?
Neutral
What colour will an alcohol turn red litmus?
It will remain red as alcohols are neutral
What test can be used to determine if a liquid is a carboxylic acid, besides litmus or UI?
Addition of a metal or carbonate or hydrogen carbonate will create bubbles of hydrogen gas
What is the product of the reaction between an amine and a carboxylic acid?
Alkyl-ammonium salt
What is the ion formed when a carboxylic acid is deprotonated by a base?
Carboxylate salt
What redox reaction can be performed to identify an alkene?
Addition of acidified permanganate which will change from purple to pink/colourless
