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. 1 Compound B has the composition 62.1% carbon, 10.3% hydrogen and 27.6% oxygen. a Calculate the empirical formula of B. [2] b From the mass spectrum, find the molecular mass of B and hence its molecular formula. [2] c i Draw displayed formulae for the possible isomers of B. [2] ii Use the 1H NMR spectrum of B to decide which isomer is B. [1] iii Explain your reasoning. [3] d Explain the main features of the 1H NMR spectrum of B. [4] e What feature of the infrared spectrum shows the identity of the functional group present in B? [2] 2 Arene C has the composition 90.6% carbon and 9.4% hydrogen. a Calculate the empirical formula of C. [2] b From the mass spectrum, find the molecular mass of C and hence its molecular formula. [2] c i Draw displayed formulae for the possible aromatic isomers of C. [4] ii When 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] d Explain the main features of the 1H NMR spectrum of C. [4] 3 Compound D has the composition 77.8% carbon, 7.41% hydrogen and 14.8% oxygen. a Calculate the empirical formula of D. [2] b Using the infrared spectrum, identify one of the functional groups present in D. [2] c From the mass spectrum, find the molecular mass of D and hence its molecular formula. [2] d i Draw displayed formulae for the possible isomers of D that contain a benzene ring. [5] ii Use the 1H NMR spectrum of D to decide which isomer is D. [1] iii Explain your reasoning. [3] e Explain the main features of the NMR spectrum of D. [4] 4 Compound E has the composition 69.8% carbon, 11.6% hydrogen and 18.6% oxygen. a Calculate the empirical formula of E. [2] b From the mass spectrum, find the molecular mass of E and hence its molecular formula. [2] c Compound E reacts with 2,4-dinitrophenylhydrazine to give a yellow–orange precipitate. Draw displayed formulae for the seven possible isomers of E. [7] d Compund E gives a silver mirror with Tollens’ reagent. Identify the functional group in E. Give evidence to support your answer from the infrared and 1H NMR spectra of E. [3] e Use the 1H NMR spectrum to identify E. Explain your reasoning. [4]

5 Compounds 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. a Give the structural formulae of the six possible isomers that have this molecular formula and that are either carboxylic acids or esters. [6] b Examine 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]

COAS Chemistry 2 Teacher Resources Original material © Cambridge University Press 2005, 2007, 2009 1 Total: Score: % 82

COAS Chemistry 2 Teacher Resources Original material © Cambridge University Press 2005, 2007, 2009 2 10 End-of-chapter test: Spectra

Compound B

Mass spectrum for B

Infrared spectrum for B

1H NMR spectrum for B

COAS Chemistry 2 Teacher Resources Original material © Cambridge University Press 2005, 2007, 2009 3 Compound C

Mass spectrum for C

Infrared spectrum for C

1H NMR spectrum for C

COAS Chemistry 2 Teacher Resources Original material © Cambridge University Press 2005, 2007, 2009 4 Compound D

Mass spectrum for D

Infrared spectrum for D

1H NMR spectrum for D

Mass spectrum for E

Infrared spectrum for E

1H NMR spectrum for E

COAS Chemistry 2 Teacher Resources Original material © Cambridge University Press 2005, 2007, 2009 6 13C NMR spectra for F, G and H

Compound F

Compound G

Compound H