Chemistry 2022 · Oct/Nov · Paper 22

Species such as NH , CO and PO are examples of molecular ions.

Ionic and covalent bonds both involve an electrostatic attraction between different species. Identify the species that are electrostatically attracted to one another in:

Complete Table 1.1 to show the total numbers of protons and electrons in the molecular ions , CO and PO Table 1.1 molecularion total number of protons total number of electrons

NH is a Brønsted-Lowry acid.

Define Brønsted-Lowry acid.

When NH

is heated with NaOH(aq), a pungent gas is produced. Write an ionic equation for this reaction.

The nitrogen atom in NH is sp hybridised. sp orbitals form from the mixing of one 2s and three 2p orbitals. Sketch the shapes of a 2s and a 2p orbital on the axes in Fig. 1.1.

There are many naturally occurring hydrated compounds that contain the anion PO

Name the anion PO

Struvite is a soft hydrated mineral with M = 245.3. The anhydrous form of the mineral has the formula NH MgPO Calculate the number of molecules of water of crystallisation in struvite. Give your answer to the nearest integer. Show your working. number of molecules of water of crystallisation =

reacts with 2-bromo-2-methylpropane in an S 1 reaction. The molecular ion (CH forms as the intermediate in this reaction.

Draw the mechanism for the S 1 reaction of OH with 2-bromo-2-methylpropane. Include charges, dipoles, lone pairs of electrons and curly arrows as appropriate. Draw the structures of the organic reactant and organic product. CC H

2-bromo-2-methylpropane is a tertiary bromoalkane. Define tertiary bromoalkane. Draw the structure of M. [1] [Total: 17]

The chlorides of some of the Period 3 elements are shown in Table 2.1. Table 2.1 bonding C C structure S S oxidation state of Period 3 element

Complete Table 2.1. Use C = covalent, I = ionic, M = metallic. Use G = giant, S = simple. [4] with water. Include state symbols in both equations. NaCl .

as shown.

State the effect of an increase in temperature on the equilibrium mixture in equation 1. Explain your answer. and the pressure in the flask is Use the ideal gas equation pV = nRT to calculate the M of the Period 3 chloride. Deduce its formula. = formula of Period 3 chloride = [3] of Br

Describe what is observed. Explain your answer. has M = 103.1 and is a liquid at room temperature. SBr has M = 191.9 and is a gas at room temperature. and SBr . Give your answer in terms of intermolecular forces.

Bismuth is a dense metal in the same group as phosphorus.

Draw a labelled diagram to show the bonding in bismuth metal. [2] is a solid at room temperature. It melts when heated gently. reacts vigorously with water at room temperature to form an acidic solution. . Explain your answer. [Total: 21]

Organic compounds can be distinguished using chemical tests and analytical techniques.

Table 3.1 shows four pairs of organic compounds. Table 3.1 organic compounds reagent positive result of chemical test on identified compound D1 D2 OHCH

Complete Table 3.1 to: result. Use a different reagent for each test.

A1 and A2 are structural isomers. Define structural isomers.

Give the systematic name of B2.

Deduce the molecular formula of D1.

D2 forms polymer Z when heated gently.

Identify the type of polymer that forms from D2.

Draw one repeat unit of polymer Z.

Organic compound E contains three carbon atoms. E reacts with cold dilute acidified KMnO

to form a single compound F with M = 154.9. Fig. 3.1 shows the infrared spectrum of E. Fig. 3.2 shows the infrared spectrum of F. transmittance/ % 4000 3000 2000 wavenumber / cm 1500 1000 500 transmittance/ % 4000 3000 2000 wavenumber / cm 1500 1000 500 Table 3.2 bond functional group containing the bondcharacteristic infrared absorption range C-O hydroxy, ester 1040-1300 C=C aromatic compound, alkene 1500-1680 C=O amide carbonyl, carboxyl ester C-H alkane 2850-3100 N-H amine, amide 3300-3500 O-H carboxyl hydroxy owing to C-H bonds in each molecule.

Use the two infrared spectra and Table 3.2 to identify the functional group present only in E. functional group explanation

Use the infrared spectrum of F to identify the functional group formed when E reacts with cold dilute acidified KMnO

functional group explanation

The mass spectrum of E shows a molecular ion peak and an M+2 peak of approximately equal abundance at m/e = 120 and 122. Deduce the relative molecular mass, M , of E. =

Use the information in 3

to suggest a structure for E.

Complete the equation for the reaction of E with cold dilute acidified KMnO

to form F. In the equation, [O] represents cold dilute acidified KMnO

C2 can be synthesised using A1 as a single organic reactant.H O Devise a multi-step synthetic route to form C2 from A1. Identify relevant reagents and conditions, and state the organic products of each step. [Total: 22] Important values, constants and standards Faraday constant F = 9.65 u 10 Avogadro constant L = 6.022 u 10 electronic charge e = ?1.60 u 10?19 molar volume of gas V at room conditions ionic product of water K = 1.00 u 10?14 Group The Periodic Table of Elements hydrogen 1.0 He helium 4.0 12131415161718 34567891011123Li lithium 6.9 beryllium 9.0 atomic number atomic symbolKey name relative atomic mass sodium 23.0 magnesium 24.3 potassium 39.1 calcium 40.1 rubidium 85.5 strontiu m 87.6 caesium 132. 9 barium 137.3 francium Ra radium boron10.8 13 Al aluminium 27.0 31 Ga gallium 69.7 49 In indium 114.8 thallium 204.4 carbon 12.0 14 Si silicon 28.1 32 Ge germanium 72.6 50 Sntin 118.7 82 Pb lead 207.2 titanium 47.9 40 Zr zirconium 91.2 72 Hf hafnium178. 5 rutherfordium vanadium 50.9 41 Nb niobium 92.9 73 Ta tantalum 180.9 105 Db dubnium chromium 52.0 42 Mo molybdenum 95.9 74 W tungste n 183.8 106 Sg seaborgium manganese 54.9 43 Tc technetium rhenium 186. 2 107 Bh bohrium iron 55.8 44 Ru ruthenium 101.1 76 Os osmium 190.2 108 Hs hassium Co cobalt 58.9 45 Rh rhodium 102.9 iridium192.2 109 Mt meitnerium nicke l58.7 46 Pd palladium 106. 4 platinum 195. 1 110 Ds darmstadtium copper 63.5 47 Ag silver 107. 9 79 Au gold 197. 0 111 Rg roentgenium zinc 65.4 48 Cd cadmium 112.4 80 Hg mercury 200. 6 112 Cn copernicium flerovium livermorium nitrogen 14.0 phosphorus 31.0 33 As arsenic 74.9 51 Sb antimony 121.8 bismuth 209.0 oxygen 16.0 sulfur 32.1 34 Se selenium 79.0 52 Te tellurium 127.6 84 Po polonium fluorine 19.0 17 Cl chlorine 35.5 35 Br bromine 79.9 iodine 126.9 Ne neon 20.2 18 Ar argo n39.9 krypto n 83.8 54 Xe xenon131. 3 86 Rn radon nihonium moscovium tennessine oganesson scandium 45.0 yttriu m 88.9 57?71 lanthanoids 89?103 actinoids 57La lanthanum 138.9 89 Ac lanthanoids actinoids actinium Ce cerium 140.1 90 Th thoriu m232.0 praseodymium 140.9 91 Pa protactinium 231.0 neodymium 144.4 uranium 238.0 promethium neptunium samarium 150.4 94 Pu plutonium europium 152.0 95 Am americium gadolinium 157.3 96 Cm curium terbiu m158.9 97 Bk berkelium dysprosium 162. 5 californium holmium 164. 9 99 Es einsteinium erbium 167. 3 100 Fm fermium Tm thulium168. 9 101 Md mendelevium ytterbiu m 173. 1 102 No nobelium lutetium 175.0 lawrencium To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge Assessment International Education Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cambridgeinternational.org after the live examination series.