Organic Practical skills

Question 1

Write an equation for the oxidation of propane-1,2-diol under reflux, using (o) to represent the oxidising agent

Show the displayed formula of the organic product

Answer 1

Check physical flashcards for answers

Question 2

Anti bumping granules are placed in the flask when refluxing. Suggest why these granules prevent bumping

Answer 2

To form smaller bubbles

Question 3

State the purpose of anti-bumping granules

Answer 3

To prevent vigorous boiling

Question 4

Outline the method the student used for recrystallisation

Answer 4

• Dissolve minimum volume of water/solvent
• Dissolve in a hot solvent
• Filter off the pure product under reduced pressure
• Leave to cool to recrystallise

Question 5

Outline how you would carry out simple laboratory process to show that the recrystallised product is a pure sample of N-phenylethanamide

Answer 5

• Measure the melting point of N-phenylethanamide
• Use of melting point apparatus
  -Sharp boiling point

Question 6

Assume the reaction goes to completion. Suggest three practical reasons why the percentage yield for this reaction may not be 100%

Answer 6

• Product left in the beaker/ glassware
• Sample was still wet
• Sample lost during recrystallisation

Question 7

Explain why the student might prefer to use ethanoic anhydride, even though it has a slower rate of reaction

Answer 7

HCl gas, violent reactio, harmful

Question 8

You are provided with a small sample of pure aspirin in a melting point tube. Describe briefly how you would determine an accurate value for the melting point of aspirin

Answer 8

• Heat melting point in an oil bath
• Slowly near the melting point