C16/28 - Practical techniques

Question 1

What does the quickfit apparatus consist of?

Answer 1

• round bottom/ pear shaped flask.
• receiver.
• screw tap adapter.
• condenser.
• still head.

Question 2

What is heating under reflux and the apparatus?

Answer 2

Heating under reflux is a procedure used to prepare an organic liquid without boiling off the solvent, reactants, or products.
Allows liquid to be boiled continuously during reaction preventing volatile components escaping.
- quickfit apparatus equipment.
- rubber tubing, stand and clamp.
- heat source (heating mantle, bunsen etc). Water bath used if reaction takes place below 100*C.

Question 3

Key points when setting up reflux apparatus?

Answer 3

• heating mantle used for flammable liquids so no naked flame is present.
• reaction mixture+ anti bumping granules added to flask before fitting the condenser.
• anti bumping granules to stop large bubbles which make the glass vibrate violently from forming.
• condenser kept upright and clamped loosely as it’s fragile.
• no stopper on condenser as closed system would be created and pressure builds up (explosion).
• water enters at bottom, leaves at top to ensure outer jacket is full.