Post-Lab Questions, Reduction Lab Calculations hydride - Towson University

Post-Lab Questions, Reduction Lab Calculations: 1. Calculate the moles of vanillin used in your reaction. 2. Calculate the moles of sodium borohydride used, based on the concentration of the

sodium borohydride solution. 3. Based on your answer in (2), calculate the moles of hydride in the reaction. 4. For every one aldehyde, one hydride is needed for the reduction process. Identify

which component, vanillin or hydride, is the limiting reagent and calculate the theoretical yield of vanillyl alcohol, in grams. 5. Calculate the percent yield of vanillyl alcohol produced in your reaction.

Post-Lab Questions, Reduction of Vanillin

1. Analyze the infrared spectra of vanillin, found in the lab handout. Indicate each

significant peak and the corresponding bond causing the vibration on each IR. Submit b

with report.

Be sure to indicate all identifiable bonds, including each of the following bonds on the IR

where the stretches would be found.

Aromatic Ring: sp2C ?H, pseudo C=C

Phenolic hydroxyl group: H-O, C-O

Aldehyde: C=O, aldehyde sp2C-H

Alkyl groups: sp3C-H

Ether: C-O

2. Analyze the infrared spectrum of vanillyl alcohol Indicate each significant peak and

the corresponding bond causing the vibration on each IR. Submit with report.

Aromatic Ring: sp2C ?H, pseudo C=C

Alkyl groups: Sp3 C-H

Hydroxyl groups (both): H-O, C-O

Ether: C-O

Type the remaining responses: 3. Explain why vanillin cannot be easily dissolved by water. 4. Explain why the sodium salt of vanillin is readily soluble in water. 5. If you incorrectly add acid and do not attain a pH of 1, your yield may be lower than

it should be as some of your product would not be isolated. Why won't it be isolated? 6. Conversion Calculation: Your solution in the lab contained 80 mg NaBH4 per milliliter.

With this in mind, show the conversion and calculate how much solution is required to reduce 0.3000 g vanillin. 7. If a student's product has a melting point result of 106.2-110.4?C, is it possible that the isolated compound is the starting aldehyde? Explain. 8. Cite YOUR melting point and determine if you made vanillyl alcohol and how pure it is.

 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download