3.3.6 Organic analysis Flashcards
1
Q
How would you test for an alcohol?
A
- Add acidified potassium dichromate
- Colour change from orange to green, 1y and 2y alcohols
2
Q
What two ways can you test for an aldehyde?
A
- Tollen’s reagent; silver mirror forms
- Fehling’s solution; brick-red ppt forms
3
Q
How do you produce Tollen’s reagent?
A
- Add NaOH to a test tube of silver nitrate solution until a brown ppt forms (silver oxide)
- Then add conc. ammonia solution dropwise until the solution dissolves
4
Q
How do you test for an alkene?
A
- Add bromine water
- Goes colourless from orange-brown
5
Q
How do you test for a carboxylic acid?
A
- Add sodium carbonate/hydrogencarbonate
- Effervescene, test gas by bubbling through lime water (turns cloudy if carbon dioxide was produced)
6
Q
What is the unique region called on the IR spectrum?
A
Fingerprint region
7
Q
State the meaning of the term molecular ion.
A
Molecule with one electron knocked off
8
Q
State why the Mr for carbon-12 is exactly 12.00000
A
- It is the standard value
- By definition it is exactly 12
