PRACTICAL SKILLS - PAG 6 - PREPARATION OF A PURE ORGANIC SOLID

Three tasks based around the synthesis of aspirin cover techniques of recrystallisation, filtering under reduced pressure, melting point determination and thin layer chromatography. The last 2 techniques are used to determine level of purity of sample made.

[johnobmasca]

just amazing..keep up the good work sir..

[NA-bbbq]

How do you know when to purify by recrystallisation and when to purify filtration?

[xetrmkw]

Hi there- another great video. Just wanted to ask why minimum hot water is needed to recrystalise, why you need to cool before filtering and why cold water is used to wash away impurities?

Thanks in advance

[neilhughes]

Will we need to know this specific example for the exam or could they ask you about a similar reaction and expect you to apply the method? (as in do we need to know the specific reactants etc.)

[mooodlemip]

seeing as it tells us the percentage yield, surely were meant to use that in our calculation of mass of 2-hydroxybenzoic acid needed? otherwise well end up getting 14.5% less aspirin than is asked for