Deduce the structure of a molecule from its 1H NMR spectrum using the number of signals (distinct hydrogen environments), chemical shifts compared with the data booklet table and the integration ratio giving the relative numbers of protons.
The mass spectrum of carbonyl dibromide is shown below. Bromine has two isotopes, and , of almost equal abundance. (i) Explain the origin of the peaks that appear at m/z values smaller than those of the molecular ion. (ii) Deduce…
The compound X shown below occurs naturally in cocoa and coffee and is used as a flavouring agent. (i) State the name of the functional group found in compound X. (ii) Deduce the IUPAC name of X. (iii) Deduce how many signals the NMR spectrum of X…
The NMR spectrum of an alcohol with molecular formula shows four signals with relative areas 6 : 4 : 1 : 1. Which alcohol is it? A. Pentan-1-ol B. Pentan-3-ol C. 2-methylbutan-2-ol D. 2,2-dimethylpropan-1-ol
Which oxygen-containing compound gives this low-resolution NMR spectrum? A. Propanone B. Methyl ethanoate C. Propanoic acid D. Propan-2-ol
In the mass spectrum of Y, the molecular ion peak appears at m/z 88. (i) Y contains no multiple carbon–carbon bonds and no rings. Deduce its molecular formula. Use section 7 of the data booklet. Shown below is the high-resolution NMR spectrum of Y,…
Which is the low-resolution NMR spectrum of methyl methanoate, ? A. Spectrum A B. Spectrum B C. Spectrum C D. Spectrum D
(i) Draw the structural formula of 2-chloropentane and that of the structural isomer in which the chlorine atom is attached to a tertiary carbon atom. (ii) Only one of the two isomers drawn in (c)(i) is chiral. Draw stereochemical formulas showing its two…
The NMR spectra of four compounds are described below. Which is the spectrum of propanone, ? Use section 21 of the data booklet. A. one singlet at 2.2 ppm B. a quartet at 2.4 ppm and a triplet at 1.0 ppm, with relative areas 2 : 3…