Question

1) Which of these choices best describes the interpretation of a ¹H NMR spectral peak that was recorded as 1.85  (2H, t)? The underlined hydrogen atom is intended to be the one producing the peak that we are interpreting.

CH-CH2

CH2-CH2

CH3-CH2

CH2-CH2-CH2

CH3-CH2-CH3

None of these interpretations describes this peak.

2) What would be the partial interpretation (concerning the number of chemically equivalent hydrogen atoms in a molecule) of a doublet which integrates for 1 H and is located at 11 in the ¹H NMR? For this question, consider only the integration of the peak.

CH2

CH

CH3

2 equivalent CH2

2 equivalent CH

3) What would be the partial interpretation (concerning the number of chemically equivalent hydrogen atoms in a molecule) of a triplet which integrates for 2 H and is located at 2.5  in the ¹H NMR? For this question, consider only the integration of the peak.

2 equivalent CH

2 equivalent CH2

CH3

CH2

CH

4) What would be the partial interpretation (concerning the number of chemically equivalent hydrogen atoms in a molecule) of a triplet which integrates for 2 H and is located at 3.5 in the ¹H NMR? For this question, consider only the integration of the peak.

CH

CH2

2 equivalent CH2

2 equivalent CH

CH3

5) What would be the partial interpretation (concerning the number of chemically equivalent hydrogen atoms in a molecule) of a singlet which integrates for 2 H and is located at 7.5 in the ¹H NMR? For this question, consider only the integration of the peak.

CH2

CH3

2 equivalent CH

CH

2 equivalent CH2

Answer 1

② Ans CH₂-CH2 a = S = 185 ppm, + 2H. rule per n+ above ? molecule gives triplet as where n= adjacent H. atom. Hence it gives triplet. 2 Ans = 2 -equivalent CH. e- CH_CH- (a) adjacenth one a= doublet it has only / cetem. 2 equivalent of CH2 Ans 0 eg -CH2-CH2-C- (+) nti rule - CH2 CH 2 - ca) a gives triplet as per Ans - 2 equivalent CH2 le.g CH2-CH 2-0 (+) - CH2 - CH2 - cas a = gives triplet. ans = -CH- CH3 (a) eg. (a) CH2-CH3 Het a = Singlet at 7.5 ppm (ZH)