Organic analysis

Question 1

Test for alcohol

Answer 1

• Heat w/ acidified potassium dichromate
• 1º - orange to green
• 2º - orange to green
• 3º - nothing

Question 2

Fehling’s solution

Answer 2

• Warm w/ fehling solution
• Aldehyde - blue sol to brick red ppt
• Ketone - nothing

Question 3

Tollen’s reagent

Answer 3

• Add silver nitrate
• Add dilute sodium hydroxide sol, brown ppt
• Add dilute ammonia sol
• Heat
• Aldehyde - silver mirror
• Ketone - nothing

Question 4

Test for carboxylic acid

Answer 4

• Solid sodium carbonate
• Carboxylic acid - sol fizz + CO₂ turn limewater cloudy

Question 5

Outline how infrared spectroscopy helps identify organic molecules

Answer 5

• Beam of IR radiation passed through sample
• IR radiation absorbed by covelant bonds inc vibrational molecules
• Bonds btw diff. atoms absorb diff. freq.