6 (3.6) Test for alcohol, aldehyde, alkene, carboxylic acid Flashcards

1
Q

Test for alcohol: metal

A
  1. Add a small piece of metallic sodium​ ​to alcohol.
  2. Produces hydrogen gas which is shown by ‘squeaky pop’ test.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Safety precautions for test for alcohol: metal

A
  1. Dispose any excess sodium safely using the beaker of ethanol provided. (Sodium will completely react with the excess ethanol in order to be safely washed away because if any water comes into contact with the sodium there is a serious fire risk)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Test for alcohol: potassium dichromate

A
  1. add acidified potassium dichromate to the solution, heat in hot water bath
  2. Primary and secondary alcohols will reduced from orange dichromate(VI) ions to green chromium(III) ions.
  3. It will remain orange if a tertiary alcohol is present.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Test for alkene?

A

-add bromine water, shake tube
-bromine water decolourises from orange if alkene present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Test for carboxylic acid?

A

-add solid sodium carbonate
-effervescence/ fizzing of CO2 gas
-bubble through limewater- turns cloudy if CO2 produced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Formula for limewater turning cloudy?

A

Ca(OH)2 + CO2 —> CaCO3 + H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Equation for testing for alcohol test? (Ethanol)

A

3CH3CH2OH + Cr2O7^2- + 8H+ —> 3CH3CHO + 2Cr^3+ + 7H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Test for halogenoalkand?

A

-add NaOH solution + warm
-add dilute nitric acid + silver nitrate solution
-if haloalkane present- precipitate form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Results for tests for halogenoalkanes?

A

Chloride ions (Cl-) = white ppt
Bromide ions (Br-) = cream ppt
Iodide ions (I-) = Yellow ppt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Test for aldehyde?

A

-add Fehlings solution to sample
-if aldehyde present- red ppt forms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly