Organic Analysis

Question 1

What reagent is used to test for alcohols

Answer 1

Sodium metal

Question 2

What is a positive result of a sodium test for alcohols

Answer 2

Effervescence.
Gas produced produces squeaky pop in lit splint

Question 3

What oxidising agent can be used to test for alcohols and what does it produce

Answer 3

Potassium Dichromate
Colour change from orange to green
For 1 and 2 alcohols that are oxidised

Question 4

What reagent is used to test for an aldehyde
What is the positive result

Answer 4

Fehling’s reagent
Clear blue to brick red precipitate

Question 5

What reagent is used to test for alkenes and what is the positive result

Answer 5

Decolourises brown bromine water

Question 6

What reagent is used to test for carboxylic acids

Answer 6

Sodium Carbonate

Question 7

What is the result of adding sodium carbonate to COOH

Answer 7

Gas produced turns limewater cloudy

Question 8

What is the test for halogenoalkanes

Answer 8

Add NaOH to release halide ions
Add Nitric acid and then Silver nitrate

Question 9

How are infrared spectra produced

Answer 9

IR is fired at molecules
Covalent bonds absorb the IR
This causes the bonds to vibrate
Different bonds vibrate at different frequencies

Question 10

Name the two ways IR spectra can be used to identify a molecule

Answer 10

Fingerprint region
Key troughs for funcitonal groups

Question 11

Name the 4 stages of Mass Spec

Answer 11

Ionisation (spray or electron impact)
Acceleration
Drift
Detection