Please answer all questions for points. thanks in advance friends!!!!! 1. What i

Question

Please answer all questions for points. thanks in advance friends!!!!!

1. What is the difference between melting and dissolving an organic compound? Is there a phase change when both melting and dissolving an organic compound? 2. What is the general purpose of recrystallization? 3. How are absorbed impurities that are trapped in the crystal lattice of the solid released during recrystallization? Where do these impurities ultimately end up? 4. What does the filtration of the hot solutions achieve during recrystallization? What is left on the filter paper and what is collected in the suction flask? 5. What does the filtration of the cold solutions achieve during recrystallization? What is left on the filter paper and what is collected in the suction flask?

Explanation / Answer

1)melting is when a substance changes frm de solid to the liquid state, often due to a rise in temperature.
but dissolving is when a substance is added to a solvent and mixes with it to form a new substance. There will be phase change in melting but in dissolving there may be a phase change.

2)The purpose of recrystalization is to purify the compound being recrystalized. This may seem difficult but it is m

Solid organic products are typically generated from a reaction mixture with impurities trapped in their crystal lattice. In order to release these "occluded" impurites and purify the organic product, recrystallization is often necessary.

Recrystallization involves dissolving the impure (crude) product in a minimal amount of hot solvent so that the solution is saturated with the product crystals, and then cooling the saturated solution so that the crystals come out of solution, leaving the impurities dissolved in the solvent.

In order for this process to work, the solvent must be chosen so that it:

uch easier and cheaper that other methods of purification.

4)Hot filtration[2] can be used to separate "compound A" from both "impurity B" and some "insoluble matter C". This technique normally uses a single-solvent system as described above. When both "compound A" and "impurity B" are dissolved in the minimum amount of hot solvent, the solution is filtered to remove "insoluble matter C". This matter may be anything from a third impurity compound to fragments of broken glass. For a successful procedure, one must ensure that the filtration apparatus is hot in order to stop the dissolved compounds crystallizing from solution during filtration, thus forming crystals on the filter paper or funnel.

5)For most recrystallizations it is best to find a solvent where your desired product is soluble hot but not cold and your
impurities are very soluble at all temperatures. Add, in portions, just enough hot solvent to completely dissolve the solid
in an Erlenmeyer flask. Allow the contents of the flask to cool to room temperature, then cool the solution further in an
ice-water bath. (Be careful

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