3.3.6.1 Identification of functional groups by test-tube reactions Flashcards
1
Q
How can you distinguish between a ketone and aldehyde?
A
Use either Tollens’ reagent or Fehling’s solution.
If positive, (i.e. if aldehyde is present) it forms a silver mirror (Tollens’) or Blue solution turns to brick red ppt (Fehling)
There is no change in the presence of a ketone
2
Q
How can we test for carboxylic acids?
A
Use sodium carbonate/ sodium hydrogencarbonate
If carboxylic acid present, there is effervescence/ fizzing.
3
Q
How can we test for CO2
A
Bubble through lime water
Turns cloudy if present
