U4-2-2 - Distillation and Reflux

Question 1

What should be added to a round-bottom flask before heating it?

(Reflux/distillation)

Answer 1

Anti bumping granules

Question 2

What is the purpose of anti bumping granules?

Answer 2

Allows liquids to boil smoothly and calmly.

Question 3

How does heating under reflux prevent loss of volatile substances during heating?

Answer 3

As substances vapourise and enter the condenser, they are cooled, condense into liquid and drip back into the reaction vessel.

Question 4

Complete the labels on this reflux setup

Answer 4

Question 5

Why does the water go in at the bottom of the condenser?

Answer 5

This allows the condenser to fill up fully and remain cold even if the water stops flowing (otherwise it would flow out).

Question 6

Name this piece of equipment

Answer 6

Condenser

Question 7

What can distillation be used for? (2)

Answer 7

1. Identification (by determining b.p.)
2. Purification (separation by b.p.)

Question 8

What is the purpose of heating under reflux?

Answer 8

Allows extended heating
OR
prevents vapours escaping