Interpretation:Solvents or mixture of solvents that can be considered for recrystallization of solids A and b should be explained.
Concept introduction:Criteria mentioned below should be used to select solvent for recrystallization.
1. Solvent 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
EBK EXPERIMENTAL ORGANIC CHEMISTRY: A M
- In fractional distillation, liquid can be seen running from the bottom of the distillation column back into the distilling flask. What effect does this returning condensate have on the fractional distillation?arrow_forwardDescribe the ideal condition/set-up for recrystallization of substances. What are the factors to consider? Explain your answer.arrow_forwardAn ideal recrystallization solvent should have a large gradient of solubility along with temperature, has the ability to dissolves the impurities very well and must not chemically react with the product. For each of the three reasons given, give an explanation for why they are a reason that make an ideal recrystallization solvent?arrow_forward
- Briefly explain how slow cooling contributes to the formation of pure crystals during recrystallization.arrow_forwardA chemist is given a nonelectrolyte white powder for analysis. 38.7 g of this substance is dissolved in 100.0 g of water. It is determined that the resulting solution freezes at -4.0°C. Additionally, the elemental composition of the substance is identified and found to be 40.0% C, 6.7% H and 53.3 % O by mass. Find the molecular formula of this unknown white powder using these experimental evidences (Kr of water: 1.86°C/m, C: 12 g/mol, H: 1 g/mol, O: 16 g/mol).arrow_forward1. What limitations are encountered in the application of sublimation as a general method of purification? 2.Explain how a process of fractional sublimation might be applied to a mixture of two substances which sublime closely together.arrow_forward
- 6. Calculate the polydispersity of the polymer sample in the colloid solution having 1:2:1 ratio of the number of moles of polymer chains of exact molecular weights 482.00, 2768.00, and 5308.00 g/mol respectively. A. 1.36 В. 1.26 С. 1.10 D. 1.06 Е. 1.03arrow_forwardIn a mixed solvent system, what is the role of the "poor" solvent? a.to DECREASE the solubility of the solute in the good solvent and saturate the solution b. to INCREASE the solubility of the solute in the good solvent and saturate the solution c. to DECREASE the boiling point of the mixturearrow_forwardWhy is potassium hydrogen phthalate (KHP) used to standardize the NaOH solution instead of measuring out a known mass of solid NaOH to be dissolved in water? KHP is an acid and will neutralize some of the NaOH to use later. O There is no reason, NaOH solutions can be used without standardization. O Solid NaOH is hygroscopic and will absorb water, making it virtually impossible to determine a true initial mass and therefore changing the concentration of the solution. Solid NaOH evaporates therefore its concentration can never be known.arrow_forward
- Chemistry for Today: General, Organic, and Bioche...ChemistryISBN:9781305960060Author:Spencer L. Seager, Michael R. Slabaugh, Maren S. HansenPublisher:Cengage LearningChemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage Learning
- General Chemistry - Standalone book (MindTap Cour...ChemistryISBN:9781305580343Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; DarrellPublisher:Cengage LearningPhysical ChemistryChemistryISBN:9781133958437Author:Ball, David W. (david Warren), BAER, TomasPublisher:Wadsworth Cengage Learning,Macroscale and Microscale Organic ExperimentsChemistryISBN:9781305577190Author:Kenneth L. Williamson, Katherine M. MastersPublisher:Brooks Cole