I need to make a presentation and I need to explain what is important in the Rec
ID: 923148 • Letter: I
Question
I need to make a presentation and I need to explain what is important in the Recristallization if is right according with the data I sent before. I have to explain the result and conclusion. I need something not too long, just good enough. Could be the melting point, the solvent, etc. I will appreciate your help. Amount purified Acetanilide recovered = 0.43g Percentage recovery = (0.43g/1.5g) x 100 = 28.67% Melting point of crude Acetanilide= Ti = 85.9 - Tf = 99.6 -mp= 92.75oC Melting point of purified Acetanilide = Ti=94.0 -Tf=103.2-mp=98.6 oC I need to make a presentation and I need to explain what is important in the Recristallization if is right according with the data I sent before. I have to explain the result and conclusion. I need something not too long, just good enough. Could be the melting point, the solvent, etc. I will appreciate your help. I need to make a presentation and I need to explain what is important in the Recristallization if is right according with the data I sent before. I have to explain the result and conclusion. I need something not too long, just good enough. Could be the melting point, the solvent, etc. I will appreciate your help. Amount purified Acetanilide recovered = 0.43g Percentage recovery = (0.43g/1.5g) x 100 = 28.67% Melting point of crude Acetanilide= Ti = 85.9 - Tf = 99.6 -mp= 92.75oC Melting point of purified Acetanilide = Ti=94.0 -Tf=103.2-mp=98.6 oCExplanation / Answer
The principle behind recrystallization is that the amount of solute that can be dissolved by a solvent increases with temperature. For example, if you wanted to purify a sample of Compound X which is contaminated by a small amount of Compound Y, an appropriate solvent would be one in which all of Compound Y dissolved at room temperature because the impurities will stay in solution and pass through filter paper, leaving only pure crystals behind. Also appropriate would be a solvent in which the impurities are insoluble at a high temperature because they will remain solid in the boiling solvent and can then be filtered out. When dealing with unknowns, you will need to test which solvent will work best for you.
The melting point of a compound is one way to test if the substance is pure. A pure substance generally has a melting range (the difference between the temperature where the sample starts to melt and the temperature where melting is complete) of one or two degrees. Impurities tend to depress and broaden the melting range so the purified sample should have a higher and smaller melting range than the original, impure sample.So, crude m.p is lower than purified acetanilide