The Spectra of Compounds B to H Are on the Sheets Provided

10 End-of-chapter test

Spectroscopy

The spectra of compounds B to H are on the sheets provided.

1Compound B has the composition 62.1% carbon, 10.3% hydrogen and 27.6%oxygen.

aCalculate the empirical formula of B.[2]

bFrom the mass spectrum, find the molecular mass of B and hence its molecular formula.[2]

ciDraw displayed formulae for the possible isomers of B.[2]

iiUse the 1H NMR spectrum of B to decide which isomer is B.[1]

iiiExplain your reasoning.[3]

dExplain the main features of the 1H NMR spectrum of B.[4]

eWhat feature of the infrared spectrum shows the identity of the functional group
present in B?[2]

2AreneC has the composition 90.6% carbon and 9.4% hydrogen.

aCalculate the empirical formula of C.[2]

bFrom the mass spectrum, find the molecular mass of C and hence its molecular formula.[2]

ciDraw displayed formulae for the possible aromatic isomers of C.[4]

iiWhen C is chlorinated with just one chlorine atom, only one isomer is possible.
Use this evidence and the NMR spectrum of C to decide which isomer is C.[5]

dExplain the main features of the 1H NMR spectrum of C.[4]

3CompoundD has the composition 77.8% carbon, 7.41% hydrogen and 14.8%oxygen.

aCalculate the empirical formula of D.[2]

bUsing the infrared spectrum, identify one of the functional groups present in D.[2]

cFrom the mass spectrum, find the molecular mass of D and hence its molecular formula.[2]

diDraw displayed formulae for the possibleisomers of D that contain a benzene ring.[5]

iiUse the 1H NMR spectrum of D to decide which isomer is D.[1]

iiiExplain your reasoning.[3]

eExplain the main features of the NMR spectrum of D.[4]

4Compound E has the composition 69.8% carbon, 11.6% hydrogen and 18.6% oxygen.

aCalculate the empirical formula of E.[2]

bFrom the mass spectrum, find the molecular mass of E and hence its molecular formula.[2]

cCompound E reacts with 2,4-dinitrophenylhydrazine to give a yellow–orange precipitate.Draw displayed formulae for the seven possible isomers of E. [7]

dCompundEgives a silver mirror with Tollens’ reagent.Identify the functional group in E.
Give evidence to supportyour answerfrom the infrared and1H NMR spectra of E.[3]

eUse the 1H NMR spectrum to identify E.Explain your reasoning.[4]

5Compounds F, G and H have the molecular formula C4H8O2.
When aqueous solutions of F and G are added to sodium carbonate, effervescence is seen.
H has no effect.

aGive the structural formulae of the six possible isomers that have this molecular formula
and that are either carboxylic acids or esters.[6]

bExamine the carbon-13 NMR spectra of F, G and H. Identify them from the ‘wet results’
given above and the 13C NMR spectra. Explain your reasoning.[6]

Total: Score: %

10 End-of-chapter test: Spectra

Compound B

Mass spectrum for B

Infrared spectrum for B

1H NMR spectrum for B

Compound C

Mass spectrum for C

Infrared spectrum for C

1H NMR spectrum for C

Compound D

Mass spectrum for D

Infrared spectrum for D

1H NMR spectrum for D

Compound E

Mass spectrum for E

Infrared spectrum for E

1H NMR spectrum for E

13C NMR spectra for F, G and H

Compound F

Compound G

Compound H