RP 5 - Distillation of a reaction product

Question 1

What is distillation?

Answer 1

Distillation is a technique where a liquid is heated to create a vapour which is cooled by a condenser, causing the gas to condense into a liquid and drip into a separate flask. The species separate due to relative volatilities and boiling points

Question 2

What equipment is used for distillation?

Answer 2

• Distillation is either done with:
  1. Semi-micro distillation apparatus
  2. Quickfit apparatus (pear-shaped or round-bottomed flask with a liebig condenser, still head, stopper, receiver, adaptor, fitted with a thermometer and collection vessel)

Question 3

What does a diagram of Quickfit apparatus set up for distillation look like?

Answer 3

There’s a round-bottom flask with a liquid inside labelled ‘Impure products’. The flask is connected to a ‘T-shaped still head’ which’s top is connected to a ‘thermometer’ and it’s side is connected to a ‘Leibig condensor’ which has its ‘water in’ and ‘water out ‘ on the same side (facing up). The other side of the Leibig condensor is connected to another round-bottom flask with a liquid labelled ‘Distillate’.

Question 4

What agent is often used in distillation?

Answer 4

Oxidising Agent

Question 5

Why are anti-bumping granules used in distillation?

Answer 5

To allow smooth boiling - preventing bubbles caused by vapour to cause upwards splashing in the flask

Question 6

How do you isolate a liquid product?

Answer 6

You can use a separating funnel to isolate the organic layer from the aqueous layer. Shake the flask. Allow the layers to separate. Then open the tap and run off one layer into a separate container

Question 7

What are some common potential hazards, risks and control in the lab during Distillation?

Answer 7

• Bunsen burner risks burning so keep away from flammable chemicals and away from the edge of the desk
• Chemicals may: be an irritant or corrosive, causing irritation to skin, eyes and lungs; be toxic, be flammable so handle with care and while wearing gloves. Wear eye protection. Keep away from the edge of the desk and from an open flame. Don’t ingest
• Glassware like beakers or test tubes risks breaking or cutting you so handle with care and keep away from edge of the desk