The infrared spectrum of an organic compour8j ,zb )lm,1cdw*zk; kahf1 9tz)bjznd is shown.

What are the units of the variable X, shown on the $x$-axis of the infrared spectrum?

  What is the correct IUPAC a 2 r n+atm4cggy-w*m;czb -,oname of this molecule?

  Which of the following represent saturated cotroupb;3kga 2ne19 :pt2r oy/mpounds?
I. 3-methyl-1-butyne
II. Propanol
III.

  Which of the following statements is not correct fo.3k4 kyqin3 8bz6mq ikr the class of organic molecules?4kq. min8kbi3 zyqk 36

  Which functional groups are present in this molecul tf5(;eq ne(kue?

I. Amine
II. Ester
III. Ether

  Which molecule is correctly identified as anp.qd jhvzy 0gu)gc-7y+nt,x; amide?

  What functional groups are both present in the following organic bku++u 9zbhn- molecule?

1.Determine the missio0cg nwtw4,x(0q -m nfng name and structure using IUPAC naming rules.
IUPAC Name Structural formula
2,3-dimethylbutane


2.Determine whether the following molecules are primary, secondary or tertiary halogenoalkanes.
Molecule Primary, secondary or tertiary
$CH_3CHClCH_2CH_3$
2-bromo-2-methylbutane

  The electromagnetic spectrum is divided into s- ju5l, u9q+ qjbxgi1tj95 9e3 wobwfdifferent types of radiation as showewfs9 5lqj 3xwtqjj99,uo5bu+i-g1b n.

In one spectroscopic technique, electromagnetic radiation is used to identify functional groups based on the vibrational frequencies of their chemical bonds. Which of the following wavelengths of electromagnetic radiation would be most useful for this technique?

  A 3D model of a molecule wit.43ip b sustf2h two chiral centers is shown.

Which structural formula correctly illustrates the arrangement of bonds in this molecule?

1.Complete the table below with the missing -g*sgcotrs* yh2v+.:k b cc4 zformulae or structures.

Molecular name	Empirical formula	Molecular formula	Structural formula
Ethene
Butanoic acid

2.Name and give correct structural formula for 2 isomers of $C_3H_6O_2$ hat contain a carbonyl group.

  Which of the following isfnysnwdt0 16g6g6 g stpbe20:3ssd n2 an example of unsaturated hydrocarbons?

I. $CH_4$​
II. $CH_3Cl$
III. $C_2H_4$​
IV. $C_2H_2$​

  Compound X has a molecular mass of 148.
The mass spectrum of compound X contains a peak at m/z = 117.
Which of the following spectral fragments is lost from compound X to produce this peak in the mass spectrum?
Atomic masses (amu) C=12C=12, H=1H=1, O=16O=16

  The respective names of the monop3y ,grw rj4v9ym7 gj7mer and polymer in the below polymerization reaction are:mgpwgvj7,7 yjy3 49 rr

Compounds X and Y have the following structural formulas.


1.The IR spectrum of compound Y features a signal that is not present in the IR spectrum of compound X. Using section 26 (section 20- 2025 Syllabus) of the data booklet, state the range of wavenumbers in which this IR signal occurs.
2.The $^1H$NMR spectrum of compound X was recorded using electromagnetic radiation with a wavelength of $1m$.
The spectrum contains two signals with chemical shifts of 3.47 and 1.21 $ppm$. The integral of the signal at $1.21ppm$ is set to a value of 1.
(1)State the type of electromagnetic radiation used in this experiment, using section 3 (section 5- 2025 Syllabus) of the data booklet.
(2)Calculate the integral of the signal at $3.47ppm$.
(3)Suggest two features that would be present in the $^1H$NMR spectrum of Y but not in the spectrum of X, using section 27 (section 21 NS) of the data booklet.
3.The mass spectrum of one of the compounds is shown.



1.State the $m/z$ value of the molecular ion peak.
2.Explain how the identity of the compound can be determined from the peak at $m/z$ = 43, using section 28 ($section 22- 2025 Syllabus$) of the data booklet.

  Which of the following molecules containf q0*aehj9cf 4s a tertiary amine?

The IR and $^1H$ NMR spectra of compound C are shown.



Compound C contains one $CH_3$ group and one functional group. The $^1H$ NMR signals of the compound do not change if a base is added to the NMR sample.
1.Using section 27 ($section 21- 2025 Syllabus$) of the data booklet, determine the number of $CH_2$ groups in compound C.
2.Using sections 26 and 27 (sections 20 and 21- 2025 Syllabus) of the data booklet, identify the functional group in compound C. 3.Give two reasons for your answer.
4.Draw the full structural formula of compound C.
The empirical formula of compound C was confirmed by measuring its elemental composition. Using your answer to (c) and section 6 (section 7- 2025 Syllabus) of the data booklet, calculate the expected abundance of carbon as a percentage of the molar mass.

  A carboxylic acid has t*i50pxyljiw e 2(dvn 4he following structural formula.



The $^1H NMR$ NMR spectrum of the carboxylic acid is measured. Which of the following correctly describes the pattern of signals in the $NMR$ spectrum?

  Which pairs of molecules are structural uw (*kahi4fyz2/:nk o isomers of each other?

  Which of the following compounds could form a racemic mixtuaflm8 g8:b* gfb wre9yi)+5pjr)wxa0 u vl:-rre with (+)-menthol? j85xrwb *-iu frw +0lgrag)v la89) :pyemb:f

  Which row gives the correct number ofd 3-t n0y7spd,ha2s6/wq ( 6unygy hit peaks and integration values for the structure , hwsg-6t3 yy ypdd/t2nuh 67i(sq an0below?

  The $^1H$ NMR spectrum of compound A is shown.

Which of the following is a possible structural formula of compound A?

  The structural formulae of thtd0mm) 6vr502io hu3dl k 0-ujbugjr.ree compounds are shown.

A student measures the optical activities of the three compounds using a polarimeter. Which of the following results are they most likely to obtain?

  The structural formulas of two compoundp)q(r0v g39)(qb qcpsfk ,wzb s in a homologous series are shown.

Why does the boiling point of compound Y differ from that of compound X?

Properties and behaviors of organg/-6 6onay/y(oxa.mqwk8 t jn ic molecules can be inferred using intermolecular forank(6 tawo/8/yoy.n mgxqj6-ces.
Explain, giving a reason, which of the following pairs will have a higher boiling point:
1.Propane, butane.
2.Ethanol, ethanoic acid.
3.Propanol, propanone.

Compound A is a drug historically used for the treatment of insomnia. It consists only of carbon, hydrogen and oxygen atoms.
1.The IRIR spectrum of compound A contains a weak signal at $−12116\,cm^{−1}$ and a strong broad signal at $13450\,cm^{−1}$. There are no strong signals between 1500 and $12000\,cm^{−1}$.
State the names of the two functional groups present in compound A, using section 26 ($Section 20- 2025 Syllabus$) of the data booklet.
2.The mass spectrum of compound A is shown.

(1)State the $m/z$ value of the molecular ion peak.
(2)Using section 28 ($Section 22- 2025 Syllabus$) of the data booklet, suggest how the fragment ion peaks with $m/z$ values of 69 and 83 are formed.
3.The $^1H\,NMR$ spectrum of compound A is shown.


(1)Using section 27 ($Section 21- 2025 Syllabus$) of the data booklet, explain the relative sizes of the integrals for the signals at 0.96 and $2.86\, ppm$.
(2)Explain the splitting patterns of the signals centred around 0.96 and $1.64ppm$. 4.Based on your answers to (a), (b) and (c), draw the full structural formula of compound A.

A polymer P has a repeat unit with the following struc9x9t,aqxq11hhw 1my dtural formula.


1.State whether the carbon atom labelled with an asterisk (*) is primary, secondary or tertiary, giving a reason for your answer.
2.Polymer P is produced via the addition polymerisation of compound A.
(1)Draw the full structural formula of compound A.
(2)Compound A has two structural isomers that contain the same functional groups. State the IUPAC names of compound A and both structural isomers.
(3)State the observation when compound A is mixed with aqueous bromine.
(4)An organic compound can also be identified by measuring the mass of carbon dioxide and water produced when each gram of the compound undergoes complete combustion. The equation for the combustion of another compound B is shown.
$B$ +12 $O_2$ →8 $CO_2$+8 $H_2O$Explain why compound A could not be distinguished from compound B using this method.

  Compound Y has the molecular-r; qhjxx-c1z.w,ic s formula C4H8O2CX​HX​OX​ and produces the following c -h,z xj.iw1 sx-crq;IR spectrum.
Which gives a possible structure for Y?
($IR\,absorptions: C=O: 1700−1750\,cm^{−1}$;
O−H ($alcohol$): 3200−3600 $cm^{−1}$ ($broad$);
O−H ($carboxylic acid$): 2500−3000 $cm^{−1}$ ($very broad)$)

  The mass spectrum of an alcohol was found to contain major peaks at m/z 1bu-kx iupam6q7 s*m172yyh d702, 57, amy*p6bd 7kyihq1- 7 m2s7auxund 45.

Which of the following compounds could this spectrum belong to?

  The mass spectrum of compound X features a fragment ion peak a ),9js227l*b vbuc;qs befn b4qs 7i 1bspkd(dt an $m/z$value 31 units lower than the molecular ion peak.
The $^1H$ NMR spectrum of the compound is shown.


Which of the following is the most likely structural formula of compound $X$?
Atomic masses ($amu$):C=12, H=1H=1, O=16O=16

  The $^1H$ MR spectrum of alkane A is shown.

Which of the following is a possible condensed structural formula of alkane A?.

  When pentan-2-one undergoes complete combustion, carbon *;wl/c d b zltp)(ow;ddioxide and water are the only products. The equation fort /lc(p do)z ;l*w;dwb this reaction is shown.
Pentan-2-one+a $O_2$ →b$ CO_2$+$b H_2O$
What are the values of a and b in this equation?

Compound X contains carbon, hydrogen, and oxygen onnt, cztvl9+n4ai 9*k(z(a 30fmvxhqo ly.
1.Combustion of 50.0 $g$ of compound X in excess oxygen produced 107.8 $g$ $CO_2$, and 44.1 $g$ $H_2O$. Determine the empirical formula of compound X.


2.Using the mass spectrum above, state and explain the molecular formula of compound X.
3.A high-resolution mass spectrum of the same compound revealed a major peak at m/z = 57. Refer to section 28 ($Section 22- 2025 Syllabus$) of the Data Booklet to deduce the identity of the ion responsible.

4.Use Section 26 ($Section 20- 2025 Syllabus$) of the Data Booklet to identify the bonds responsible for peaks I and II on the IR spectrum above.
5.The peaks and relative intensities for the 11H NMR spectrum are given in the table below. Use Table 27 ($Section 21- 2025 Syllabus$) of the Data Booklet and your answers to (b), (c) and (d) to deduce the structure of X.
Chemical shift (ppm) is 0.9 ; Relative peak intensity is 6
Chemical shift (ppm) is 1.5 ; Relative peak intensity is 1
Chemical shift (ppm) is 2.2 ; Relative peak intensity is 2
Chemical shift (ppm) is 11.5 ; Relative peak intensity is 1