[neals000]

hi good day all. im really in need of some help. these are practice questions for my final exam and  im not understanding what to do

A compound X gives the following IR spectral data: 2700-3300 cm-1, 1725 cm-1, 1600 cm-1, 1450 cm-1. Upon reaction with sodium borohydride followed by acidification, the
product Y, with the following 1H NMR spectral data is formed.
The 1H NMR data for Y
Draw the structures of the starting material, X and product Y, and assign/label the 1H
NMR signals in Y. (Hint: Molecular formula of Y is C9H12O)



This question is related to the compound with the empirical formula C8H8O2.
a) From the NMR data identify the structural moities obtained: Singlet at 3.7 ppm (3 H); multiplet at 7.2 ppm (5 H)     (2 marks)     
b) From the IR data identify the functional groups in the compound: 2850 cm-1 (sharp), 1720 cm-1, 1600 cm-1, 1503 cm-1     (4 marks)       
c) From the MS data identify the fragments as shown in Figure 4.1 (5 marks)   

attached is the practice exam

[neals000]

any one? help, please?
 

[Burner]

You need to show your attempts to the question before others can help you. (Forum Policy: http://www.chemicalforums.com/index.php?topic=65859.0)

Hint: How can you use the IR spectral data and molecular formula?

[Dan]

You must show that you have attempted the question, this is a Forum Rule.

You have posted Q3 from the pdf, regarding a compound C₉H₁₂O, but all the important information (NMR data and question number) is missing in your post. Then you have posted a different question (Q4) underneath, which refers to a different compound (C₈H₈O₂), without clearly indicating that it is a different question. The result is that your post doesn't make much sense unless the reader downloads the pdf and tries to match what you have posted to the exam paper. The more effort required by the reader, the less likely you are to attract helpful responses. I recommend posting the question(s) in full with your attempts/ideas at solving them, and we can take it from there.

[orgopete]

To add to Dan's comment, I pretty snooty. Unless I can see the actual problem, I skip them. If you are going to post a link to your problem, I'm not going to click it. I'd say if you want our help, don't make us work for it. Think about how you are stuck and you'll probably get a better answer.

[Babcock_Hall]

Do you know how to calculate the degree of unsaturation from a molecular formula?  That is often a good place to start.