Chemistry 9701/13 October/November 2020: question paper and mark scheme

Question

Which statement is correct? A Cl has a relative isotopic mass of 35.5. B Cl 2 has a relative molecular mass of 70. C ICl has a relative molecular mass of 162.4. D NaCl has a relative molecular mass of 58.5.

Question

Strontium metal can be extracted from strontium oxide, SrO, by reduction with aluminium. One of the possible reactions is shown. 6SrO + 2Al → 3Sr + Sr3Al 2O6 What is the maximum mass of strontium metal that can be produced from the reduction of 100 g of strontium oxide using this reaction? A 41.3 g B 42.3 g C 84.6 g D 169.2 g

Question

A single 32P nucleus can be produced when a single 32S nucleus joins with particle X. In the process a proton is emitted. What is particle X? + A a deuteron, 21H B an electron C a neutron D a proton

Question

In which of the following, when in liquid form, are there only intermolecular forces based on temporary dipoles between the particles? A bromine B ethanol C hydrogen chloride D water

Question

Copper has a high melting point. What is the reason for the high melting point of copper? A strong attractive forces between copper atoms only B strong attractive forces between copper ions and delocalised electrons C strong attractive forces between copper ions only D strong attractive forces between copper atoms and delocalised electrons

Question

Which pair of standard enthalpy changes are numerically equal? A atomisation of CH4(g) and formation of CH4(g) B combustion of CH3OH(l) and combustion of graphite + 2(combustion of H2(g)) C combustion of graphite and formation of CO2(g) D neutralisation of HCl (aq) with NaOH(aq) and formation of H2O(l)

Question

An energy cycle is drawn for the following reaction. Br2(l) + 3F2(g) → 2BrF3(l) 2Br(g) + 6F(g) +698 kJ 2BrF3(g) Br2(l) + 3F2(g) 2BrF3(l) The standard enthalpy of formation of BrF3(l) = –301 kJ mol–1. The enthalpy change of BrF3(l) to BrF3(g) is +44 kJ mol–1. What is the average bond energy of the Br–F bond in BrF3? A 152 kJ mol–1 B 202 kJ mol–1 C 304 kJ mol–1 D 404 kJ mol–1

Question

In which reaction does the greatest change in the oxidation number of sulfur occur? A S(s) + O2(g) → SO2(g) 1 B SO2(g) + O (g) 2 2 SO3(g) C SO3(g) + H2SO4(l) → H2S2O7(l) D H2S2O7(l) + H2O(l) → 2H2SO4(l)

Question

The first stage in the chloride process for the manufacture of titanium consists of the following reaction. 2TiO2 + 4Cl 2 + 3C → 2TiCl 4 + 2CO + CO2 What is reduced in this reaction? A carbon B chlorine C oxygen D titanium

Question

In aqueous solution, sulfuric acid dissociates as shown. H2SO4 → HSO4– + H+ This reaction goes to completion. HSO4– SO42– + H+ This reaction reaches equilibrium with constant Kc. Analysis of a 2.00 mol dm–3 solution of H2SO4 found the HSO4– concentration to be 1.988 mol dm–3. What is Kc? A 1.381 × 105 dm3 mol–1 B 82.34 dm3 mol–1 C 1.214 × 10–2 mol dm–3 D 7.244 × 10–5 mol dm–3

Question

An autocatalytic reaction is a reaction in which one of the products catalyses the reaction. Which curve would be obtained if the rate of an autocatalytic reaction is plotted against time? A B C D rate rate rate rate 0 0 0 0 0 time 0 time 0 time 0 time

Question

X and Y are two elements in Period 3 of the Periodic Table. They combine to form compound Z. X forms a soluble acidic oxide. The oxidation number of X in this oxide is +4. Y forms an amphoteric oxide. What is the formula of compound Z? A Al P B Al 2S3 C Si2P5 D SiS2

Question

This question is about two elements in Group 2, Q and R. Three of the statements shown are correct for metal Q. The one remaining statement is correct for metal R. Which statement applies to R? A A saturated solution of the hydroxide of this metal has the higher pH value. B This metal has a carbonate that is used in agriculture to reduce the acidity of soil. C This metal has the greater atomic radius. D This metal reacts more quickly with cold water.

Question

The electronic arrangement for atoms of four elements is given. Which element is the strongest oxidising agent? A 1s22s22p5 B 1s22s22p63s2 C 1s22s22p63s23p5 D 1s22s22p63s23p64s2

Question

A student mixes pairs of chemicals together in separate test-tubes. ● excess calcium (s) + water (l) ● barium chloride (aq) + strontium hydroxide (aq) ● calcium carbonate (s) + excess hydrochloric acid (aq) ● magnesium sulfate (aq) + barium nitrate (aq) How many of the mixtures produce a white, solid product? A 0 B 1 C 2 D 3

Question

With which compound does concentrated sulfuric acid react both as a strong acid and as an oxidising agent? A magnesium carbonate B potassium chloride C sodium bromide D sulfur trioxide

Question

Ammonia can undergo an acid–base reaction with hydrogen chloride to form ammonium chloride. Which statement is correct? A The ammonium ion is basic. B The hydrogen atom from HCl donates a lone pair of electrons to the nitrogen atom. C The H–N–H bond angle in ammonia is the same as the H–N–H bond angle in the ammonium ion. D The H–N–H bond angle in the ammonium ion is the same as the H–C–H bond angle in methane.

Question

What are the trends in the stated properties as Group 2 is descended from magnesium to barium? decomposition temperature of the first ionisation energy carbonate A decreases increases B decreases decreases C increases increases D increases decreases

Question

Sulfur dioxide, SO2, reacts with calcium hydroxide in aqueous solution. What is the main product that is first formed? A Ca(HSO4)2 B CaS C CaSO3 D CaSO4

Question

Structural and stereoisomerism should be considered when answering this question. Compounds X, Y and Z are shown. X Y Z HO HO Cl H H Cl Cl OH How many other isomers of C3H7Cl O are there that are alcohols? A 2 B 3 C 4 D 5

Question

Two students each make a statement about 2-methylbut-1-ene. Student 1 states that 2-methylbut-1-ene has geometrical isomers. Student 2 states that 2-methylbut-1-ene reacts with HBr in an addition reaction to give 1-bromo-2-methylbutane as the main product. Which students are correct? A both 1 and 2 B 1 only C 2 only D neither 1 nor 2

Question

Which statement is correct when referring to the complete combustion of PVC? A A gas is made which contributes to global warming. B Carbon dioxide and water are the only products. C If water is used to clean the exhaust gases, the water becomes alkaline. D There is no need to treat the exhaust gases as the products are non-hazardous.

Question

Iodoethane, CH3CH2I, reacts with aqueous silver nitrate at 50 °C. A precipitate forms during this reaction. Which row of the table is correct about this reaction? type of organic reaction colour of precipitate A electrophilic substitution cream B electrophilic substitution yellow C nucleophilic substitution cream D nucleophilic substitution yellow

Question

A student converts 1-iodopropane, C3H7I, into butanoic acid, C3H7CO2H, by a two-stage chemical synthesis. In the first of the two stages, which reagent is reacted with 1-iodopropane? A aqueous sodium hydroxide B ethanolic ammonia C ethanolic potassium cyanide D ethanolic sodium hydroxide 25 1-chloro-1-methylcyclohexane is hydrolysed by heating with NaOH(aq). CH3 CH3 + OH– → + Cl – Cl OH The reaction pathway is shown. energy Z reaction pathway One carbon atom in 1-chloro-1-methylcyclohexane is bonded to three other carbon atoms. What is the charge on this carbon atom at point Z? A 1– B δ– C δ+ D 1+

Question

In the question paper above.

Question

An alcohol with the molecular formula C5H12O decolourises warm acidified potassium manganate(VII). The alcohol also gives a yellow precipitate with alkaline aqueous iodine. What could be the identity of the alcohol? A 2-methylbutan-2-ol B 3-methylbutan-2-ol C pentan-1-ol D pentan-3-ol

Question

Which pair of test results would prove that a substance, X, is a ketone? A X has no reaction with Tollens’ reagent. X reacts with alkaline aqueous iodine. B X is reduced by lithium aluminium hydride. X is oxidised by acidified dichromate(VI). C X reacts with 2,4-DNPH reagent. X has no reaction with Fehling’s reagent. D X reacts with hydrogen cyanide. X is reduced by lithium aluminium hydride.

Question

Carvone is found in spearmint oil. carvone O Which product is formed when carvone is reacted with NaBH4? A B C D OH O O OH

Question

Which compound is chiral and reacts with Na2CO3 to give CO2? A B C D CH3 OH CH2Br CH(Br)CO2H H CO2H C HCO2CH CH2 C CH3 H CO2H CH3

Question

The skeletal formula of compound X is shown. compound X HO What is the molecular formula of compound X? A C10H18O B C10H20O C C11H22O D C11H24O Section B For each of the questions in this section, one or more of the three numbered statements 1 to 3 may be correct. Decide whether each of the statements is or is not correct (you may find it helpful to put a tick against the statements that you consider to be correct). The responses A to D should be selected on the basis of A B C D 1, 2 and 3 1 and 2 2 and 3 1 only are only are only are is correct correct correct correct No other combination of statements is used as a correct response. Use of the Data Booklet may be appropriate for some questions.

Question

Nitrogen forms a number of oxides. Their enthalpies of formation are given. [NO(g)] = +90 kJ mol–1 [N2O(g)] = +82 kJ mol–1 [NO2(g)] = +33 kJ mol–1 Which statements are correct? 1 If N2O(g) is oxidised by O2(g) to NO2(g), 16 kJ is released per mole of N2O. 2 The decomposition of N2O(g) to N2(g) and O2(g) is exothermic. 3 The reaction between NO and oxygen is exothermic.

Question

Which statements are correct? 1 enthalpy of combustion of H2 = enthalpy of formation of H2O 2 enthalpy of formation of H2 = –(enthalpy of atomisation of H2) 3 enthalpy of solution of HCl = enthalpy of hydration of H+ + enthalpy of hydration of Cl –

Question

The units of Kc for an equilibrium reaction are mol–1 dm3. What could be the equation for the equilibrium? 1 A(aq) + B(aq) C(s) + D(aq) 2 P(aq) + Q(aq) R(aq) 3 W(aq) + 2X(aq) Y(aq) + Z(aq)

Question

Methanol, CH3OH, can be produced industrially by reacting CO with H2. CO(g) + 2H2(g) CH3OH(g) ΔH = –91 kJ mol–1 The process can be carried out at 4 × 103 kPa and 1150 K. Which statements about this reaction are correct? 1 Increasing the temperature will increase the rate of reaction because more effective collisions will occur. 2 Lowering the temperature will reduce the rate of reaction because the forward reaction is exothermic. 3 Increasing the pressure will reduce the rate of reaction because there are a larger number of moles on the left-hand side of the equation.

Question

Which rows correctly show the relative electrical conductivities of the sets of three Period 3 elements? greatest least conductivity conductivity 1 sodium silicon chlorine 2 aluminium magnesium phosphorus 3 sulfur silicon phosphorus

Question

Three test-tubes, X, Y and Z, each contain water. ● A small amount of NaCl is added to test-tube X. ● A small amount of SiCl 4 is added to test-tube Y. ● A small amount of Al Cl 3 is added to test-tube Z. After a short time, two drops of universal indicator solution are added to each test-tube. Which statements can be correct? 1 The pH in test-tube X is 7. 2 The pH in test-tube Y is 2. 3 The pH in test-tube Z is 2. The responses A to D should be selected on the basis of A B C D 1, 2 and 3 1 and 2 2 and 3 1 only are only are only are is correct correct correct correct No other combination of statements is used as a correct response.

Question

The structure of compound R is shown. compound R O OH O Which statements about compound R are correct? 1 It has an Mr of 116. 2 It contains two groups that show strong absorptions between 1640 and 1740 cm–1 in its infrared spectrum. 3 Its only infrared absorption between 2500 and 3000 cm–1 is sharp and strong.

Question

During the bromination of methane, the free radical CH3• is generated. A possible termination step of this reaction is the formation of C2H6 by the combination of two free radicals. What could be produced in a termination step during the bromination of propane? 1 CH3CH2CH(CH3)CH2CH3 2 CH3CH(CH3)CH(CH3)2 3 CH3CH2CH2CH(CH3)2

Question

Three reactions of primary alcohols are listed. Which reactions give water as one of the products? 1 reaction with ethanoic acid 2 reaction with concentrated HBr 3 passing the alcohol vapour over heated Al 2O3

Question

The diagram shows part of the structure of polymer X. CH3 H CH3 H CH3 H C C C C C C H CO2CH3 H CO2CH3 H CO2CH3 Which reagents react with polymer X? 1 aqueous sulfuric acid 2 aqueous sodium hydroxide 3 sodium