Say what?CMATT said:I also know water and ethanol are not miscible.
Sorry my chemistry book is confusing! I misreadBystander said:Say what?
alchemistf9 said:Water and ethanol are miscible!
Phthalic acid must be highly soluble in ethanol but not in water at room temp and therefore is a bad solvent for recrystallization. In order to have properly recrystallization the compound must be insoluble or only partially soluble in the solvent at room temperature but highly soluble in the solvent at or near its boiling point.
A solvent should also not react with the compounds ...CMATT said:Homework Statement
Why is ethanol a bad choice for recrystallization of phthalic acid?
2. The attempt at a solution
I know phthalic acid is very soluble in water, so water is a great candidate to recrystallize phthalic acid. I also know water and ethanol are not miscible. But I don't know how to properly answer this question. Please help.
Recrystallization is a technique used in organic chemistry to purify solid compounds. It involves dissolving the compound in a solvent, then allowing it to slowly cool and form crystals. Through this process, impurities are left behind in the solution while the desired compound forms pure crystals.
The solvent chosen for recrystallization should be able to dissolve the compound at high temperatures, but not at low temperatures. It should also be volatile and non-toxic. Additionally, the solvent should have a high boiling point to allow for slow cooling and crystal formation. A common solvent used for recrystallization is water.
The ideal temperature for recrystallization varies depending on the compound being purified. Generally, a temperature just below the boiling point of the solvent is used to ensure complete dissolution of the compound. The solution is then slowly cooled to allow for crystal formation.
Recrystallization is considered complete when no more crystals form upon cooling the solution. The solution should also appear clear and free of any impurities. A simple test for completeness is to take a small sample of the solution and allow it to evaporate. If pure crystals are left behind, recrystallization is complete.
Recrystallization is a common method used in organic chemistry for purification because it is relatively simple and does not require specialized equipment. It also allows for the purification of large quantities of compounds and can be repeated multiple times to achieve a high level of purity. Additionally, recrystallization is a gentle process that does not involve harsh chemicals, making it a more environmentally friendly purification method.