Chemistry 9701/13 May/June 2020: question paper and mark scheme

Question

Which particle has equal numbers of protons and neutrons and an electronic structure of 1s22s22p63s23p6? 39 40 2+ 16 2 − 32 A 18 Ar B 20 Ca C 8O D 16 S

Question

Which molecule contains six bonding electrons? A NCl 3 B H2S C C2H4 D SF6

Question

Solid carbon dioxide, CO2, is similar to solid iodine, I2, in its structure. Which statement about solid CO2 and solid SiO2 is correct? A Both solid CO2 and solid SiO2 exist in a lattice structure. B Both solid CO2 and solid SiO2 have a simple molecular structure. C Both solid CO2 and solid SiO2 have atoms joined by single covalent bonds. D Both solid CO2 and solid SiO2 change spontaneously to gas at s.t.p..

Question

The enthalpy changes of two reactions are shown. K2CO3(s) + 2HCl (aq) → 2KCl (aq) + H2O(l) + CO2(g) ∆H = –34.0 kJ mol–1 KHCO3(s) + HCl (aq) → KCl (aq) + H2O(l) + CO2(g) ∆H = +32.8 kJ mol–1 What is the enthalpy change for the reaction shown? 2KHCO3(s) → K2CO3(s) + H2O(l) + CO2(g) A –31.6 kJ mol–1 B 1.2 kJ mol–1 C 66.8 kJ mol–1 D 99.6 kJ mol–1

Question

Nitrogen reacts with oxygen to form nitrogen monoxide, NO, and nitrogen dioxide, NO2. Nitrogen dioxide reacts with water and with hydroxide ions. N2(g) + O2(g) → 2NO(g) 2NO(g) + O2(g) → 2NO2(g) 2NO2(g) + H2O(l) → HNO2(aq) + H+(aq) + NO3–(aq) 2NO2(g) + 2OH–(aq) → NO2–(aq) + NO3–(aq) + H2O(l) What can be deduced using only the information from these equations? A HNO2 is a strong acid. B HNO3 is a weak acid. C NO2 is a neutral gas. D NO is a reducing agent.

Question

Which solution has the lowest pH value? A 0.01 mol dm–3 butanoic acid B 0.01 mol dm–3 ethanoic acid C 0.01 mol dm–3 hydrochloric acid D 0.01 mol dm–3 sulfuric acid

Question

The element sulfur produces a mass spectrum with the following peaks. m / e value relative of peak abundance 32 95.02 33 0.76 34 4.20 36 0.02 Which relative atomic mass of sulfur can be calculated from these data, given to four significant figures? A 32.07 B 32.08 C 32.09 D 32.10

Question

What is the electronic configuration of an isolated Ni2+ ion? A 1s22s22p63s23p63d64s2 B 1s22s22p63s23p63d74s1 C 1s22s22p63s23p63d104s2 D 1s22s22p63s23p63d8

Question

At 200 °C aluminium chloride is a gas with Mr = 267. What is the number of covalent bonds, dative covalent bonds and Ione pairs of electrons in one molecule of aluminium chloride at 200 °C? covalent dative Ione pairs bonds covalent bonds A 6 2 0 B 6 2 16 C 6 2 18 D 3 0 9

Question

When solid KCl O3 is heated in the absence of air, a mixture of two chlorine compounds in the mole ratio of 3 : 1 is formed. Chlorine is the only element whose oxidation number changes in this reaction. What could be the oxidation numbers of chlorine in the two compounds that are formed? A +3 and –1 B +6 and +4 C +7 and –1 D +7 and +1

Question

Two reactions are shown. reaction 1 X2(g) + Y2(g) 2XY(g) 1 1 reaction 2 XY(g) 2 X2(g) + 2 Y2(g) The equilibrium constant, Kp, for reaction 1 is 0.0052. What is Kp for reaction 2? A 2.6 × 10–3 B 13.9 C 192.3 D 384.6

Question

Compound T is a white crystalline solid. When a sample of compound T is mixed with aqueous sodium hydroxide and heated, a gas is produced which turns damp red litmus paper blue. Further testing of a solution of compound T with aqueous barium chloride produces a dense white precipitate which does not dissolve when dilute hydrochloric acid is added to the mixture. What is the identity of compound T? A ammonium carbonate B ammonium sulfate C sodium carbonate D sodium sulfate

Question

Which property explains the trend in volatility of the elements going down Group 17? A decreasing covalent bond strength B decreasing van der Waals’ forces C increasing covalent bond strength D increasing van der Waals’ forces

Question

The statements apply to the elements in Group 2. Which statement is correct? A As atomic number increases, ionic radius increases. B As atomic number increases, reducing ability decreases. C As atomic number increases, first ionisation energy increases. D As atomic radius increases, first ionisation energy increases.

Question

Which element, when burned in oxygen, can form an oxide that is a reducing agent? A Na B Mg C Al D S

Question

Nitrogen oxides are removed from the exhaust gases of internal combustion engines by the action of a catalyst in a catalytic converter. Which row is correct? change in oxidation type of catalyst number of nitrogen A decrease heterogeneous B decrease homogeneous C increase heterogeneous D increase homogeneous

Question

The addition of aqueous silver nitrate to aqueous barium chloride produces a white precipitate which dissolves in an excess of dilute aqueous ammonia to form a colourless solution. The addition of an excess of dilute nitric acid to the colourless solution produces a white precipitate, Z. What is Z? A AgCl B BaCl 2 C Ba(NO3)2 D NH4NO3

Question

Which property shows an increase from calcium to barium going down Group 2? A the ease of decomposition of the carbonates B the solubility of the hydroxides C the solubility of the sulfates D the volume of hydrogen given off when 1 g of the metal reacts with water

Question

Element X is in Period 3. It reacts rapidly with water to form an alkaline solution. Which statement about the chloride of element X is correct? A It conducts electricity when molten. B It has a melting point of less than 100 °C. C It has covalent bonding. D It reacts rapidly with cold water.

Question

Structural and stereoisomerism should be considered when answering this question. When trans-pent-2-ene reacts with HBr, how many different products can form? A 1 B 2 C 3 D 4

Question

Ester P has the following structural formula. ester P O CH3C OCH2CH2CH(CH3)2 Which compounds are produced when P is hydrolysed using dilute hydrochloric acid? A CH3COCl and (CH3)2CHCH2CH2OH B CH3CH2OH and (CH3)2CHCH2CO2H C CH3CO2H and (CH3)2CHCH2CO2H D CH3CO2H and (CH3)2CHCH2CH2OH

Question

There are many non-cyclic alcohols that cannot be oxidised by warm acidified MnO4– ions. Alcohol X is the member of this set of alcohols with the lowest molecular mass. How many moles of oxygen are required for the complete combustion of 1.0 mol of alcohol X? A 3.5 mol B 4.5 mol C 6.0 mol D 6.5 mol

Question

Butanoic acid can be produced from 1-bromopropane in two steps using reagents V and W as shown. reagent V reagent W 1-bromopropane compound Q butanoic acid What could be reagents V and W? V W A KCN in ethanol HCl (aq) B KCN in ethanol NaOH(aq) C NH3 in ethanol HCl (aq) D NaOH(aq) H+ / Cr2O72–(aq)

Question

Which statement about compound T and compound U is correct? compound T compound U O O H 3C C H C CH2CH2CH3 CH(CH3)CH2CH3 A T and U are stereoisomers. B T can be distinguished from U by the use of alkaline aqueous iodine. C T can be reduced by LiAl H4 but not by NaBH4. D U can be formed by the oxidation of 3-methylbutan-1-ol.

Question

The diagram shows the infrared spectrum of an organic compound. What could be the identity of this compound? A propan-1-ol B propanal C propanoic acid D propanone

Question

Which reagent reacts with both of the –OH groups in lactic acid, CH3CH(OH)CO2H? A acidified potassium dichromate(VI) B ethanol C sodium D sodium hydroxide 27 1,2-dibromopropane can be made from 1-bromopropane in two steps. Which row is correct? step 1 step 2 A addition substitution B elimination addition C hydrolysis elimination D substitution hydrolysis 28 2-methylbut-2-ene reacts with HBr(g) to form two isomeric products. During the reaction two positively charged intermediates can be made. Which diagram shows the more stable of the two positively charged intermediates? A B C D Br + Br + + +

Question

In the question paper above.

Question

In the question paper above.

Question

The ester ethyl methanoate is prepared in a school laboratory by reacting a carboxylic acid with an alcohol. During the reaction, only 50.0% of the alcohol is converted into the ester. Which mass of alcohol is needed to prepare 10.0 g of the ester? A 3.11 g B 8.65 g C 12.4 g D 32.2 g

Question

Compound X has the structure shown. compound X O Which type of carbonyl group is present and how many chiral centres are there in one molecule of X? carbonyl chiral group centres A aldehyde 0 B aldehyde 1 C ketone 0 D ketone 1 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

Which contain one mole of the underlined substance under room conditions? 1 a balloon containing 24.0 dm3 of helium 2 a block of calcium carbonate weighing 100.1 g 3 4000 cm3 of a 0.250 mol dm–3 solution of sulfuric acid

Question

Buckminsterfullerene is a fullerene allotrope of carbon. Which statements about buckminsterfullerene are correct? 1 Buckminsterfullerene is a giant covalent molecule. 2 Buckminsterfullerene has delocalised electrons. 3 Buckminsterfullerene has strong intramolecular bonds.

Question

Gaseous sodium ions can be formed from sodium atoms. Na(s) → Na+(g) Which quantities are required to calculate the enthalpy change of formation of Na+(g)? 1 first ionisation energy of sodium 2 enthalpy change of atomisation of sodium 3 enthalpy change of formation of sodium 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 Haber process is used in industry to form ammonia from hydrogen and nitrogen. 3H2 + N2 2NH3 Which statements about the activation energy for this process are correct? 1 The activation energy for the forward reaction is the same as the activation energy for the reverse reaction. 2 The activation energy for the reverse reaction is decreased by the addition of iron. 3 The activation energy is the minimum energy that colliding particles must possess in order to react.

Question

Strontium nitrate is heated strongly for several minutes. Which statements are correct? 1 A brown gas is produced. 2 A gas is produced that relights a glowing splint. 3 A white powder remains after heating.

Question

When added to water, which oxides will not cause a change in pH? 1 Al 2O3 2 SiO2 3 P4O10

Question

Propanal reacts with hydrogen cyanide to form 2-hydroxybutanenitrile. A suitable catalyst for this reaction is sodium cyanide. NaCN CH3CH2CHO + HCN CH3CH2CH(OH)CN Which statements about this catalysed reaction of propanal with hydrogen cyanide are correct? 1 The sodium cyanide provides a stronger nucleophile than HCN. 2 The reaction can be classified as nucleophilic substitution. 3 The hydrogen cyanide molecule attacks the propanal molecule to form an intermediate ion.

Question

A reaction mechanism is shown. CH2 CH2 H2C CH2 H 2C CH2 + Cl – H 2C C Cl H 2C C H H OH HO– Which statements about this reaction are correct? 1 It is a substitution reaction. 2 OH– behaves as a nucleophile. 3 Heterolytic bond fission is involved.

Question

On complete combustion, a sample of X produces 44 g of carbon dioxide and 27 g of water. On complete combustion, a sample of Y produces 44 g of carbon dioxide and 18 g of water. On complete combustion, a sample of Z produces 22 g of carbon dioxide and 9 g of water. Which substances could be straight chain alkanes? 1 X 2 Y 3 Z 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

Which pairs are structural isomers of each other? 1 CH3CH2CH2CH2CH2CO2H and CH3CH2CH2CO2CH2CH3 2 and 3 CH3CH2CH2CH(OH)CH2CH3 and CH3CH2CH(OH)CH2CH2CH3