1.2.2 Use of apparatus and techniques Flashcards
1
Q
heating under reflux process
A
Quick fit apparatus
- pear/round shaped flask
- leibig condenser (water in at bottom, out at top)
- Bunsen burner
- stand and clamp
- put anti-bumping granules in the flask to prevent large bubbles forming, boils smoother
- never put a stopper in the top of the condenser as otherwise pressure builds up , causing apparatus to explode
- use rubber tuning to connect inlet of condenser to tap and outlet to sink
2
Q
why do you use anti-bumping when heating a reaction mixture under reflux?
A
boils more smoothly
prevents large bubbles forming that make the glassware vibrate
3
Q
definition of heating under reflux
A
continuous boiling and condensing of a reaction mixture to prevent volatile components from escaping
4
Q
distillation process
A
- flask is clamped and connected to t shaped still head adaptor, which connects to a condenser that is connected to a collecting flask (by receiver adaptor)
- heat the flask containing the reaction mixture. the most volatile components will start to boil first, condense, and drip into the collecting flask
5
Q
distillation definition
A
method used to separate a pure liquid from its impurities
6
Q
how to identify the organic layer when you have a mix of organic and aqueous
A
add water and the layer that doesn’t get bigger is organic
7
Q
how to purify and organic liquid (4 steps)
A
- add water and the layer that doesn’t get bigger is organic (other is aq)
- use a separating funnel to remove an organic layer from an aqueous layer
- dry with an anhydrous salt (e.g. MgSO₄, CaCl₂)
- redistillation
ie. distill product again within a narrower BP
8
Q
describe how to dry an organic liquid
A
- add drying agent to remove traces of water eg. CaCl₂ and MgSO₄
- place stopper on flask to prevent product from evaporating
- leave and continue adding drying agent until solid is dispersed in the sol. as a fine powder
- decant liquid from solid into another flask
