Tests Flashcards
1
Q
Test for carboxylic acids
A
- Add sodium carbonate to the sample.
- effervescence
- gas produced turns limewater cloudy
- a carboxylic acid is present.
2
Q
Test for aldehydes
A
- -Add Tollen’s reagent and heat.
- -A silver mirror indicates the presence of an aldehyde.
3
Q
Test for acyl chlorides
A
- -Add water to the sample slowly.
- If white misty fumes are given off, an acyl chloride is present.
- -Acyl chlorides release chloride ions very readily to give hydrogen chloride gas.
4
Q
Test for amines
A
- -Add universal indicator to the sample.
- -If it turns blue/purple an amine is present.
- -It will also have a fishy smell.
- Amines are basic.
5
Q
Test for alcohols
A
- -Alcohols react with carboxylic acids in the presence of sulphuric acid to make esters.
- -Add ethanoic acid to the sample, followed by sulphuric acid and heat.
- If a the mixture starts smelling sweet and fruity an alcohol was present.
6
Q
Distinguishing tests for primary, secondary and tertiary alcohols
A
- Primary alcohols can be oxidized to aldehydes.
- Secondary alcohols are oxidized to form ketones.
- Tertiary alcohols cannot be oxidized.
- -Add potassium dichromate and dilute sulphuric acid to the mixture and warm gently.
- -If the mixture goes green a primary or secondary alcohol is present.
- -If it does not go green a tertiary alcohol is present.
- If the mixture does go green, add Tollens reagent to the mixture and heat.
- Silver mirror= 1• alcohol
7
Q
Distinguish acyl chloride from chloroalkane
A
- Add water
- Acylchloride gives white fumes
- No reaction from chloroalkane
8
Q
A