methods and likely questions Flashcards
Acidify the combined sodium hydroxide extracts with 6M HCl until blue litmus turns red.
why is acid added?
What was the colour after acidifying?
to turn salt eugenol to free eugenol.
Cloudy
Extract the acidified solution with three separate 20cm3 portions of dichloromethane.
Why is dichloromethane used to extract the acidified solution?
When the dichloromethane is added to the acidified solution what happens?
Dichloromethane. Is an organic solvent used to dissolve the free eugenol (not salt form) in the acidified solution.
It separates into two layers, where the less dense water is on top and more dense (dichloromethane and the eugenol) is below.
Combine the extracts and dry with anhydrous sodium sulphate.
Why is this done?
To extract the water because the sodium sulphate would attach to the water molecules.
what apparatus is used to extract eugenol?
dean and stark apparatus
Between eugenol and benzoyl chloride which is more polar?
It is eugenol because of the OH group on eugenol.
Extract the diethyl ether solution with three separate 20 cm3 portions of 5% NaOH (dilute the bench solution approx.).
Why?
In addition of naoH what was the colour change?
To ensure efficacy of extraction, i.e to get maximum amount of eugenol possible out of the extracted.
It was yellow, because the eugenol was coming out, the yellow is the salt form
between a polar and non polar compound which one travels faster on a TLC
THE NON-POLAR COMPOUND TRAVELS FASTER BECAUSE THERE ARE LESS INTERACTIONS WITH THE SOLVENT. BUT THERE ARE MORE INTERACTIONS WITH POLAR COMPOUNDS.
what is eugenol used for?
antiseptic and dental analgesic
eugenol is only soluble in ______
DCM and ether
