What has a higher melting point 4-nitrobenzaldehyde in
methanol or 4-nitrobenzyl alcohol? And why? TLC
Ochem 1
4-Nitrobenzaldehyde on reduction with sodium borohydride (NaBH4) lead to the formation of 4-nitrobenzyl alcohol. NaBH4 can not reduce nitrogroup. Therefore, this reaction is taken place by nucleophilic attack of hydride on carbonyl group. The reaction can be monitored by TLC. TLC can use to separate compounds due to the presence of UV components. Due to the higher polarity and dipolemoment of carbonyl Group (C=O) of 4-Nitrobenzaldehyde found to be exhibited higher melting point than their corresponding alcohols and at the same time the oxygen of 4-nitrobenzyl alcohol is taken part in hydrogen bond formation.
What has a higher melting point 4-nitrobenzaldehyde in methanol or 4-nitrobenzyl alcohol? And why? TLC Ochem...
A student monitored the reaction progress of the reduction of 4-Nitrobenzaldehyde to 4-Nitrobenzyl alcohol using TLC. 30% ethyl acetate in petroleum ether was used as the elution solvent. TLC plates available in the laboratory were coated with the common absorbent silica gel (SiO2.xH2O) which contains polar hydroxyl (OH-) groups. c. The crude product moves slower than the starting material with the mobile phase in the TLC plate. Briefly explain a possible reason for the observation based on the chemical structures...
Why the Boiling point of the aqueous Methanol in a fractional distillation is higher than the boling point of the pure Methanol
* A student cools a sample in a capillary tube after melting it. Upon attempting to determine the melting point on the same sample, the stjudent does not obtain the same melting point. Why? . A student places his TLC plate in a chamber where the solvent level is higher than the starting line on the TLC. How does that affect the experiment? . A student leaves off the top of her TLC chamber. How will that affect her Rf...
Post lab questions for chromatography and melting point lab. i have a few ideas of what the answers to these questions should be, but I would like to double check. if anyone can help me, that would be so awesome. Thank you! A student cools a sample in a capillary tube after melting it. Upon attempting to determine the melting point on the same sample, the student does not obtain the same melting point. Why? A student places his TLC...
Explain why acetic acid has a higher boiling point than ethyl alcohol ?
Which has the higher melting point: Saline (SiH4) or phosphine (PH3)? Explain why. Include the correct structure of each molecule.
which of the following would you expect to have a higher melting point? explain why 3. Which of the following would you expect to have the higher melting point? Explain why. (3 marks - 1 for the answer, 2 for the explanation) CI OH
8. a. Explain why the melting point of pure phthalic acid is higher than that of pure napthalene, when the two compounds have nearly the same molecular weight. b. Explain why the melting point of pure hexane is hgiher than that of pure cyclo-hexane, when the two compounds have nearly the same molecular weight. (Hint: reffer to structures)
Assign each compound as polar or nonpolar, and explain why. Napthalene Anthracene Phenanthrene Benzophenone 9H-fluoroen-9-one 4-nitrobenzaldehyde 4-methoxybenzaldehyde 4-nitrophenol 4-methoxyphenol 2,5-dimethoxybenzyl alcohol 3,5-dimethyoxybenzyl alcohol
CUI 110 Oxygen, O2, and methanol, CH3OH, have the same mass: 32 amu. Explain why oxygen is a gas at om temperature, while methanol is a liquid at room temperature. 3 Why is the boiling point of ammonia higher than the boiling point 4 What type of interaction is responsible for sodium chloride's very high melting point? 5. What type of interaction is responsible for water's high boiling point?