core practical 5: oxidation of an alcohol Flashcards
1
Q
partial oxidation of primary alcohols
A
- to aldehyde
- acidified potassium dichromate (sulphuric acid)
- simple ditilation apparatus
2
Q
difference between conditions for full oxidation and partial oxidation
A
full: excess oxidising agent and heat under reflux
partial: limited oxidising agent and distil
3
Q
why must the thermometer bulb in distillation be at the opening of the condenser
A
measure boiling temperature of vapous
4
Q
colour change
A
orange to green
cr2o7 2- to cr3+
5
Q
why anti bumping granules
A
- surface area for bubbles to form
- prevents large bubble from forming
6
Q
why not seal condesner in heat under reflux
A
build up of gas pressure could cause explosion
7
Q
fractional distillation separates
A
liquids with different boiling points
8
Q
how to purify an organict liquid WHEN THEY ARE IMMISCIBLE
A
- put impure product into separating funnel
- add sodium hydrogen carbonate , shake, open tap intermittently to release pressure from co2 produced
- allow layers to separate, then run and discard aqueous layer
- run organic layer into conical glask and add DRYING AGENT (anhydroud sodium sulfate) until drying agent stops clumping and swirls freely . liquid appears clear
- then distill
9
Q
what layer is at the top of separation funnel
A
- organic product; lower density
10
Q
when is distillation used iN GENERAL
A
to separate and organic product from its reacting mixture
