C16 Organic Synthesis Flashcards
Describe how a quick apparatus is connected
Grease the joints using some petroleum jelly on the inside of the joints before connecting the pieces together
In a distillation setup, why is it necessary to have continuous water flow around the condenser
So that the water remains cool in order for the mixture to be distilled
Describe a method that can be used to separate immiscible liquids
Pour the mixture into a separating funnel and some distilled water
Add the stopper and invert the flask to mix the mixture
Equalise the pressure by opening the stopper as required
Continue shaking until there is no ‘whistle’ sound
To collect the water in the lower layer, open the stopper and place a beaker under the spout
Use another beaker to collect the desired organic layer
Shake the liquid with some drying agent
Name 2 drying agents
Magnesium sulphate
Calcium chloride
How to use drying agents
Add a selected drying agent to the organic product
If the drying agent forms clumps add some more until they are moving freely
Use gravity filtration to collect the dry product
Filtrate is the product
What’s does re-distillation mean
When a liquid is purified by using multiple distillations
How cane unsaturated hydrocarbon be tested? What are the observations?
Use bromine water
Add few drops of bromine water to the sample and mix well
Positive test - bromine water turns colourless
What are the reagents used to test haloalkanes and what’s are the observations
Reagents - silver nitrate, ethanol and water
Observations =
Chloro - white ppt
Bromo - cream ppt
Iodo - yellow ppt
What are the 3 reagents that can be used to test carbonyls
Acidified potassium dichromate
Fehling’s solution
Tollens’ reagent
What are the observations when acidified potassium dichromate react won’t ketones and aldehydes
Ketones - no change
Aldehyde - turns from orange to green colour
What are the observations when Fehling’s solution is reacted with ketones and aldehydes
Ketones - no change
Aldehyde - dark red ppt
What are the observations when tollens’ reagent is reacted with ketones and aldehydes
Ketones - no sliver mirror
Aldehydes - silver mirror
What are the reagents that can be used to test carboxylic acids? What are the corresponding observations
Universal indicator - pH of weak acid
Reactive metal - hydrogen effervescence
Metal carbonate - CO2 effervescence
