Paper 2- Organic analysis

Question 1

What is the test and positive result for alkenes?

Answer 1

Test: Add bromine water and shake
Positive result: goes from orange to colourless

Question 2

What is the test and positive result for halogenoalkanes?

Answer 2

Test: Heat with NaOH, acidify with nitric acid and add silver nitrate
Positive result: Precipitate

Question 3

What is the test and positive result for alcohols (not tertiary)?

Answer 3

Test: Add acidified potassium dichromate and heat
Positive result: Orange to green

Question 4

What is the test and positive result for aldehydes?

Answer 4

Test: Fehling’s solution
Positive result: Brick red precipitate
OR
Test: Tollen’s reagent
Positive result: Silver mirror

Question 5

What is the test and positive result for carboxylic acids?

Answer 5

Test: Add sodium carbonate
Positive result: Effervescence
OR
Test: Universal indicator
Positive result: Goes red

Question 6

Why is the value of Ar for carbon 12 exactly 12.0000?

Answer 6

By definition

Question 7

What is the meaning of the term molecular ion?

Answer 7

A molecule which has lost an electron

Question 8

What is the fingerprint region?

Answer 8

The region below 1500cm on an infrared spectrum and is unique to each compound

Question 9

Why does an infrared spectrum allow us to identify bonds?

Answer 9

Polar bonds absorb infra red radiation at characteristic wavelengths