The infrared spectrum of an organic compounz oh+q)q. ruiq bfcnkjky(32**8d s 4xd is shown.

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

  What is the correct IUPAC name of this molecc (as/dgnlc 9rh( ju8,ule?

  Which of the following represent saturated compou4:z6q/drcxt f m a9v)knds?
I. 3-methyl-1-butyne
II. Propanol
III.

  Which of the following statements is not correct bv3ucc :ewlr* 0b1ka*c1ir8qfor the class of organic molecul 1cc0rr1uk wqb3iel* : 8*cbvaes?

  Which functional groups are present in this molecu7p- vt+av am7 zmb42x1j yfn/ule?

I. Amine
II. Ester
III. Ether

  Which molecule is correctly iden gx*zw u-ny5-btified as an amide?

  What functional groups are both present in thvuzkc:flstno6/ mz1 q7 a6e:6e following organic molecule?

1.Determine the missing name and structure using IUPAC naming ruless(9kk(fhzcj q8uy;azh5r, f-.
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 diffe lw3j,ot3l w(ibnh p:ty+h//vrent types of radiation as sho ,p //: bj3+ttyiwv3l(own lhhwn.

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 w uc, 9 o34la2yh4w.czlazace) ith two chiral centers is shown.

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

1.Complete the table below 6yda7,bcv.or with the missing formulae 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 followin3csf fv, mj.r16b yr *avv2xb;g is 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 monomer and polymer in the below polymef lb)7b2 cyw1xrization reactio7bwxcybf12) ln are:

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 co -5x4scqne.hufg 7 ui0ri4 po(ntains 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 the following structural formulap,p2rjp y-d 6i.



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 isomers of eafa 0l ;gb0)wjcch other?

  Which of the following compounds could form a racemic mixture with (+)-menthol?:voirr z q3sh 4fk .,d0bu8+td d4or:zb h.vf d,uq is0rk+3t8

  Which row gives the correct nw o y+,q+szgn3umber of peaks and integration values for the structu3n+ w,zos+gqyre below?

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

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

  The structural formulhdg+r ;ty zma ,-.op9zae of three 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 compounds in a homologous serie*ig;rb,c gkd8y+jeyu 6x,ym2f y(:u mh 8bkb(s are shown.

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

Properties and behaviors of organic molecules can be infepz w q8o6r 3 pwpt+v;(vw+ryn-rred using intermolecular fqp p+ n3w z-yvvo8tw;pwrr6+(orces.
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 structuralfwi:isiwa2i7s 8l.(ql1j-dv 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 formula C4H8O2CX​HX​tck/f / b)c7olOX​ and produces the following IR slf/k/ coc)tb7 pectrum.
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 contaik-nt .*gfvg*wdh q)1ufo );wd n major peaks at m/z 102, 57, and 45. 1kdq;)-*gf.)gtu*fwho d nvw

Which of the following compounds could this spectrum belong to?

  The mass spectrum of compound X features a fragm,mk5dfy .d j8k3.m3:zvmr kovent ion peak at 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 co2)u1rvj+l vc*uuq. - tz xhf8ombustion, carbon dioxide and water are the only products. The equation for this reactiou+l1z*xu )2cj ot vf.rhq-vu 8n 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, zwzg,w-9,wozx ak 8t.pvkh 6:and oxygen only.
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