Inorganic And Organic Tests

Question 1

Test for alcohols

Answer 1

Acidified dichromate (vii)
1cm^3 potassium dichromate
5cm^3 dilute sulfuric acid
Few drops organic compound
Place in hot water bath + heat
P-turns green (P+S)
N-stays orange (T)

Question 2

Tests for aldehydes

Answer 2

Tollens reagent
1cm^3 silver nitrate solution
Drop sodium hydroxide solution- silver oxide precipitate
Add dilute ammonia until brown precipitate redissolves
Add few drops organic compound
Heat in water bath
P-silver mirror
N-no change
Or
Fehlings solution
1cm^3 Fehling’s solution A
Add Fehling’s solution B until blue precipitate redissolves
Add few drops organic compound
P-red precipate
N-remains blue
Heat in water bath

Question 3

Test for alkenes/ C=C

Answer 3

Add few drops organic compound
Add few drops bromine water
P-turns colourless
N-remains orange

Question 4

Test for carboxylic acids

Answer 4

Blue litmus paper
Add a few drops organic compound
P-change to red
N-no change
Or
Sodium carbonate solution
1 cm3 of sodium carbonate solution
Add a few drops of the organic compound
P-bubbles of gas (CO2)
N-no bubbles

Question 5

Test for Haloalkanes

Answer 5

Acidified silver nitrate
1cm^3 ethanol
1cm^3 silver nitrate solution
Heat in water bath (60°C)
Few drops organic compound
Place cotton wool plug losely in tube
P- precipitates White – AgCl Cream – AgBr Yellow - AgI
N-remains colourless