16.1 Organic Synthesis Flashcards
List the basic components of Quickfit apparatus
Round - bottomed or pear - shaped flask Receiver Screw - tap adaptor Condenser Still head
Why is reflux used?
Increases rate of reaction without boiling off the solvent, reactant or products
What apparatus do you need to heat under reflux?
Round - bottomed or pear - shaped flask Condenser Rubber tubing Stand and clamp Heat source ( usually Bunsen burner, tripod and gauze / heating mantle )
When should you use a Bunsen burner?
When reaction mixture temperature needs to be greater than 100°C
When reaction mixture contains non - flammable substances
When should you use a heating mantle?
When the reaction mixture temperature needs to be greater than 100°C
When the reaction mixture contains flammable sources
When should you use a water bath?
When reaction mixture temperature needs to be less than 100°C
When reaction mixture contains non - flammable substances
What are the stages of organic synthesis? Give examples
Synthesis ( reflux, anti-bumping granules, condsers,)
Extraction ( distillation, separatory funnel, aqueous layer test)
Purification ( sodium carbonate, drying agent, re-distillation )
When and why would you use anti-bumping granules?
Added to reaction mixture before reflux
Helps reaction mixture boil smoothly, as large bubbles cannot form and violent vibrations within glassware are reduced
When and how would you use a condenser?
Can be used during reflux / distillation
Warm vapours from reaction mixture rise out of flask.
Warm vapours enter condenser where it cools and condenses back into the flask.
Why are condensers useful?
They make it possible to continuously boil a reaction mixture without losing any reactant or product
When is it dangerous to use a condenser?
When the clamp is tightly clamped to the condenser
Or the top of the condenser is stoppered
When would you need to use distillation?
When the reaction mixture is in liquid form and :
the chemical reaction does not go unto completion
Or
by products are made concurrently
Why would you need to use distillation?
To separate unreacted substances and by products from desired product
How does distillation work?
Substance with lowest boiling point Evaporates / separates first Enters condenser Cools and condenses back into a liquid Dropping out of receiver and into a flask
When and why would you use a separators funnel?
Used when 2 visibly - distinct layers of liquids form your distillate
Used to separate the organic layer from the aqueous layer
( organic layer contains organic product, the aqueous layer is water and other water - soluble substances )
