a)
Interpretation:Errors in procedure that cause observed melting point of pure compound to be lower than correct melting point should be determined.
Concept introduction:Melting point is temperature that involves conversion of substance from solid to liquid state. Both liquid and solid phases are present in equilibrium with each other at this temperature.
b)
Interpretation:Errors in procedure that cause observed melting point of pure compound to be higher than correct melting point should be determined.
Concept introduction:Melting point is temperature that involves conversion of substance from solid to liquid state. Both liquid and solid phases are present in equilibrium with each other at this temperature.
c)
Interpretation:Errors in procedure that cause observed melting point of pure compound to be broad in range than correct melting point should be determined.
Concept introduction:Melting point is temperature that involves conversion of substance from solid to liquid state. Both liquid and solid phases are present in equilibrium with each other at this temperature.
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EBK EXPERIMENTAL ORGANIC CHEMISTRY: A M
- Show in a detailed manner. 1. Draw and label the set-up for melting point determination using capillary tube. 2. Differentiate melting point and melting point range.arrow_forwardFilter paper is usually a poor material on which to powder a solid sample before introducing it into a capillary melting-point tube because small particles of paper may end up in the tube along with the sample. Why is this undesirable? and how might the presence of paper in the sample make the melting-point determination difficultarrow_forwardIn order to obtain accurate data it is important to add hear slowly and steadily when the temperature gets close to the melting point of a sample. Why is necessary?arrow_forward
- 1. What is the limitation of the sublimation laboratory technique? 2. When can sublination be applied as a process of separation?arrow_forwardBrian forgot to close the end of his capillary tube when he was conducting the boiling point determination experiment. He then decided to use a lighter to close the end, making sure that it does not touch the oil. Which of the following statements is true? a. Brian did a great job in making sure that the experiment worked. It is important to close the end of the capillary tube for accurate determination of the lower limit of the sample's boiling point. b. What Brian did is dangerous as oil is a flammable substance. He should have stopped the experiment then closed the tube first before continuing. c. It is not important to close the end of the tube. He could have just proceeded with the experiment or covered the end of the tube with tape since prolonged air contact might contaminate the sample. d. Brian could have covered the end of the capillary tube with his finger, since it is not as dangerous as using the lighter on a flammable substance such as oil.…arrow_forwardBriefly describe the technique for packing a capillary melting point-tubearrow_forward
- If we give same sample to three different students in the same lab, why the result of melting point slightly differ from each other?arrow_forwardTrue or False. It is very important to regulate the temperature of the heating mantle so that the distillation occurs at a rate of about 1 drop per 2 seconds. Explain why?arrow_forwardDescribe the errors which may cause an observed melting point range of a PURE sample to be: higher than the correct melting point broad in rangearrow_forward
- When performing arecrystallization, slocent with a boiling point less must be use than the melting point of the compound being recrystallized. For benzil ( m.p.94-95C) which solvent would be best for this recrystallization? toluene (b.p. 110C) H2O (b.p.100 C) ethane( bo -98) methanol(bp64.7)arrow_forwardWhy should solid diazonium salts never be separated from their mother liquor by filtration?arrow_forwardwhy should a small volume of the cold solvent be used for rinsing the pure crystal? (recrystalization)arrow_forward
- Macroscale and Microscale Organic ExperimentsChemistryISBN:9781305577190Author:Kenneth L. Williamson, Katherine M. MastersPublisher:Brooks Cole