Organic analysis

Question 1

Test and positive result for primary and secondary Alcohols?

Answer 1

Acidified potassium dichromate, Orange -> Green

Tertiary alcohols don’t oxidise in test, potassium dichromate stays orange

Question 2

Test and positive result for Aldehydes

Answer 2

Tollen’s reagent warmed gently with solution, silver mirror forms in test tube, if not solution is colourless OR Fehlings reagent heated, Brick red precipitate forms, if not, solution stays blue.

Question 3

Test and positive result for Alkenes

Answer 3

Bromine water, goes Orange-brown to colourless in the presence of Carbon-Carbon double bond.

Question 4

Test for carboxylic acid and positive result

Answer 4

React with Sodium carbonate, if carboxylic acid present, CO2 gas is released and CO2 tested for with limewater, becoming cloudy.

Question 5

Test for Halogenalkanes

Answer 5

Add aqueous Sodium Hydroxide then warm, HN03 to acidify and then AgNO3 forms precipitate according to halogen