Practicals Flashcards
1
Q
Describe the process of preparing a pure organic solid (e.g. aspirin)
A
- dissolve the impure sample in a minimal volume of hot solvent
- filter hot solution through filter paper
- cool the filtrate by inserting beaker into ice
- filter under reduced pressure
- wash the crystals with cool solvent
2
Q
When preparing a pure organic solid, why wash the crystals in cold solvent?
A
remove soluble impurities
3
Q
When preparing a pure organic solid, why use a minimal volume of hot solvent?
A
hot to dissolve the compound and impurities, minimal volume required to get a concentrated solution so solution is saturated
4
Q
When preparing a pure organic solid, why filter the hot solution through filter paper?
A
remove insoluble impurities