TESTING FN GROUPS

Question 1

K-Perman. test

Answer 1

react KMnO4 + unsat…. reduction of purple coloured KMnO4 to colourless solution (and brown precipitate-Mn02- if alkaline)

Question 2

Describe the Lucas Test

Answer 2

Used to determine presence of an alcohol (p/s/t). The suspected alcohol is mixed with the reagent (mix of conc. HCl and ZnCl), if an alcohol is present it will produce a cloudy liquid.

Question 3

Describe the acidified K dichrom. test

Answer 3

Added to solution containing suspected alcohol. If p or s alcohol is present the Cr6+ ions reduced to Cr3+ and turns from orange to green. ALSO shows positive result for aldehydes (not ketones) - link to oxidation

Question 4

Describe the silver mirror test

Answer 4

Mix suspected oxidised alcohol (from acid. K-dichrom. test) with TOLLENS reagent (ammoniacal silver nitrate solution). If aldehyde present silver substance is formed (therefore was a p alcohol)

Question 5

List 3 tests for carboxylic acids

Answer 5

Acid-base indicator test
React w/ metal carbonate
Esterification test

Question 6

List 3 tests for -OH groups

Answer 6

Acidified K dichromate test
Lucas test
Silver mirror test

Question 7

List 2 tests for double bonds

Answer 7

Br water test
K permanganate test