Interpretation:Advantages of ethanol over
Concept introduction:Solvent used in recrystallization should have below properties.
1. It should be able to dissolve desired compound in itself at high temperatures but insoluble at low temperatures. In short, solvent with favorable temperature coefficient should be used for particular solute.
2. Solvent should be chosen in such way that impurities are either insoluble in it or remain moderately soluble in it at low temperatures.
3. Boiling point of desired solvent should be low so that it gets separated from crystals easily.
4. Boiling point of solvent should be less than melting point of solid under consideration.
5. There should be no reaction between solvent and substance that needs to be purified.
Want to see the full answer?
Check out a sample textbook solutionChapter 3 Solutions
Experimental Organic Chemistry: A Miniscale & Microscale Approach + OWLv2 with LabSkills 24-Months Printed Access Card, (NEW!!)
- 6 Assuming that hexane and water obey the required solubility criteria, why could they still not be used as a solvent pair in a mixed solvent recrystallization? Explain.arrow_forwardDiethyl ether and methylene chloride are generally not suitable for use in recrystallization, but are frequently used as extraction solvents. Explainarrow_forwardWhat is the approximate amount (mL) of 95% ethyl alcohol that will be required to dissolve the sulfanilamide in boiling ethanol? Note that Solubility of sulfanilamide in ethanol (mg/mL) is as follows: 14 mg at 0 °C; 24 mg at 20 °C; 46 mg at 40 °C; 88 mg at 60 °C; 210 mg at 80 °C. Remember that the sulfanilamide used in the experiment contains 5% wt of impurity (fluorenone); therefore, (357mg) X (0.05) = 17.85 mg impurities; hence = 357 mg -17.85 mg = X mg pure Sulfanilamide. So, (X mg) (1mL/210 mg) = Y mL (80 oC) minimum warm ethanol needed.arrow_forward
- Why was n-octanol chosen as a surrogate for natural organic phases? Why notanother solvent such as n-hexane, methylbenzene, trichloromethane, or diethylether?Why is the use of any organic solvent as general surrogate of a natural organicphase somewhat questionable?arrow_forwardRECRYSTALLIZATION & DECOLORIZATION (Organic Chemistry) 1. Propose a process or procedure by which the purity of re-crystallized benzoic acid can be proven. 2. If you are to account for the three components of the original mixture, considering that they were separated, in what form or state, and where were they after the whole process?arrow_forwardn-Pentanol is an aliphatic alcohol with many properties similar to ethanol. Explain why n-pentanol was not considered as a possible recrystallization solvent for fluorene during our laboratory experiment.arrow_forward
- Given the following statements, which would be the ideal solvent to use for recrystallization of this compound? Why? Compound X is soluble in both cold ethyl acetate and hot ethyl acetate. Compound X is insoluble in cold benzene but soluble in hot benzene. Compound X is insoluble in both cold hexanes and hot hexanes. Compound X is insoluble in cold ethanol but soluble in hot ethanol.arrow_forwardWhy should the recrystallization solvent have a fairly low boiling point?arrow_forwardUnder which circumstances is it wise to use a mixture of solvents to carry out a crystallization?arrow_forward
- 1. Why is the washing of crystals on the filter paper not as effective a process of purification as crystallization?2. How do you account for the formation of crystals of different sizes in slow and rapid crystallization process?3. What properties should ideally be possessed by a recrystallization solvent?arrow_forwardWhat are emulsions? Why do they form during extractions? How is the formation of an emulsion minimized?arrow_forwardCompare simple and fractional distillation for the separation of HEXANE and TOLUENEarrow_forward
- EBK A SMALL SCALE APPROACH TO ORGANIC LChemistryISBN:9781305446021Author:LampmanPublisher:CENGAGE LEARNING - CONSIGNMENTMacroscale and Microscale Organic ExperimentsChemistryISBN:9781305577190Author:Kenneth L. Williamson, Katherine M. MastersPublisher:Brooks Cole