Chemistry 9701/12 May/June 2019: question paper and mark scheme

Question

The Boltzmann distribution of molecular energies in a sample of aqueous hydrogen peroxide at room temperature is shown. molecules proportion of with sufficient molecules with energy to react energy, E 0 0 molecular energy, E Which diagram shows the Boltzmann distribution of molecular energies of aqueous hydrogen peroxide maintained at room temperature when a catalyst, manganese(IV) oxide, is added? A B molecules molecules with sufficient proportion of proportion of with sufficient energy to react molecules with molecules with energy to react energy, E energy, E 0 0 0 molecular energy, E 0 molecular energy, E C D molecules molecules with sufficient with sufficient proportion of energy to react proportion of energy to react molecules with molecules with energy, E energy, E 0 0 0 molecular energy, E 0 molecular energy, E

Question

Oxygen has three stable isotopes, 16O, 17O and 18O. All three isotopes are present in a sample of oxygen gas, O2, which was analysed using a mass spectrometer. How many peaks associated with the O2+ ion would be expected? A 3 B 5 C 6 D 9

Question

The first eight successive ionisation energies for two elements of Period 3 of the Periodic Table are shown in the graphs. ionisation ionisation energy energy 0 1 2 3 4 5 6 7 8 0 1 2 3 4 5 6 7 8 electron removed electron removed What is the formula of the ionic compound formed from these elements? A MgCl 2 B CaBr2 C Na2S D K2Se

Question

A σ bond is made between two carbon atoms in a molecule of ethene. Which diagram shows the orbital overlap that occurs to form this bond? A B C D

Question

The table shows some properties of four substances. Which substance could be potassium iodide? melting point electrical conductivity of solid / °C when molten A –66 poor B –39 good C 680 good D 1600 poor

Question

X, Y and Z are all gases that behave ideally and react according to the equation shown. X(g) + 2Y(g) → 2Z(g) When 3.0 mol of X and 3.0 mol of Y are placed inside a container with a volume of 1.0 dm3, they react to form the maximum amount of Z. The final temperature of the reaction vessel is 120 °C. What is the final pressure inside the reaction vessel? A 4.49 × 106 Pa B 9.80 × 106 Pa C 1.47 × 107 Pa D 1.96 × 107 Pa

Question

Which pair of substances are both simple molecular? A C60 and graphene B C60 and iodine C graphene and graphite D graphite and iodine

Question

A reaction pathway diagram is shown. M N reactants energy O P K L products progress of reaction Which row is correct? enthalpy change of activation energy of the forward reaction the reverse reaction A K M B K O C L O D P M

Question

X is either chlorine or an oxide of chlorine. X reacts with water, under suitable conditions, to form the two acids HCl and HCl O3 in the mole ratio of 1 (HCl ) : 5 (HCl O3). What could be X? A Cl 2 B Cl 2O C Cl O2 D Cl 2O7

Question

Ethyl ethanoate undergoes the following reaction. CH3CO2C2H5 + H2O C2H5OH + CH3CO2H Kc = 0.27 Equal amounts of ethanoic acid and ethanol were mixed together and allowed to reach equilibrium. At equilibrium, the concentrations of both ethanoic acid and ethanol were 0.42 mol dm–3. What is the concentration of ethyl ethanoate at equilibrium? A 0.22 mol dm–3 B 0.65 mol dm–3 C 0.81 mol dm–3 D 1.54 mol dm–3

Question

Which row is an example of heterogeneous catalysis? reaction catalyst A esterification sulfuric acid B the Contact process divanadium pentoxide C destruction of the ozone layer chlorine radicals D atmospheric formation of sulfur trioxide nitrogen dioxide

Question

Element Q readily oxidises in air. The oxide produced reacts with water to form a solution of very low pH. Where could element Q be found in the Periodic Table? period group A 2 1 B 2 14 C 3 14 D 3 15

Question

The eight elements sodium to argon are in the same period of the Periodic Table. The equation corresponding to the first ionisation energy is shown. X(g) → X+(g) + e– For which of these eight elements is the electron in this equation removed from a filled orbital? A Mg, Al, Si, P, S, Cl and Ar B Al, Si, P, S, Cl and Ar only C Mg, S, Cl and Ar only D S, Cl and Ar only

Question

Elements D and E are both in Period 3. Element D has the smallest atomic radius in Period 3. There are only two elements in Period 3 which have a lower melting point than element E. Elements D and E react together to form compound L. Which compound could be L? A MgCl 2 B MgS C Na2S D PCl 3

Question

How many of the solutions shown, when added to separate portions of magnesium sulfate solution, produce a white precipitate? HCl (aq) NH3(aq) (NH4)2CO3(aq) Ba(NO3)2(aq) A 0 B 1 C 2 D 3

Question

A white solid, Z, is soluble in water. A sample of Z is heated with a Bunsen burner until there is no further change. When the residue is shaken with water a solution is formed with no solid remaining. What could Z be? A MgCO3 B Mg(NO3)2 C BaCO3 D Ba(NO3)2

Question

An excess of chlorine was bubbled into 100 cm3 of hot 6.0 mol dm–3 sodium hydroxide. How many moles of sodium chloride would be produced in the reaction? A 0.3 B 0.5 C 0.6 D 1.2

Question

Ammonium sulfate, (NH4)2SO4, and ammonium nitrate, NH4NO3, are used as fertilisers. These salts have different percentages by mass of nitrogen. They have the same effect as each other on the pH of wet neutral soil. Which row is correct? higher percentage effect on pH of soil of nitrogen by mass A ammonium nitrate decrease B ammonium nitrate increase C ammonium sulfate decrease D ammonium sulfate increase

Question

Which reaction gives a product that is an atmospheric pollutant causing acid rain? A 3Mg(s) + SO2(g) → MgS(s) + 2MgO(s) B (NH4)2SO4(s) + Ca(OH)2(s) → 2NH3(g) + CaSO4(s) + 2H2O(l) C 2MnO4–(aq) + 5SO2(g) + 2H2O(l) → 2Mn2+(aq) + 4H+(aq) + 5SO42–(aq) D 2FeSO4(s) → Fe2O3(s) + SO2(g) + SO3(g) 20 3-methylbut-1-ene can undergo different types of reaction. Cl 1 2 Cl Which row correctly identifies the reaction types? reaction 1 reaction 2 A oxidation electrophilic addition B oxidation nucleophilic addition C reduction electrophilic addition D reduction nucleophilic addition

Question

In the question paper above.

Question

Compound X does not show cis-trans isomerism. What could be the identity of compound X? A 1,1,2-trichloropropene B 1,2,3-trichloropropene C 1-chlorobut-1-ene D 1-chlorobut-2-ene

Question

The diagram shows the repeat unit of an addition polymer. C2H5 CH3 C C CH3 C 2H 5 n What is the correct name for the monomer that would form this polymer? A cis-1,2-diethyl-1,2-dimethylethene B cis-2-ethyl-3-methylpent-2-ene C trans-2-ethyl-3-methylpent-2-ene D trans-3,4-dimethylhex-3-ene

Question

A molecule of geraniol is shown. geraniol OH What is formed when geraniol is reacted with an excess of cold, dilute, acidified manganate(VII) ions? A B O OH OH HO HO HO HO OH OH O O C D O + O + O O OH OH O OH OH

Question

Alcohol W cannot be made by reducing a carboxylic acid with LiAl H4. Alcohol W gives only one product when dehydrated with concentrated sulfuric acid. What could be the identity of W? A butan-1-ol B butan-2-ol C propan-1-ol D propan-2-ol

Question

Which product can be made from bromoethane by an elimination reaction? A ethanol B ethene C ethylamine D propanenitrile

Question

Propene, bromine and hydrogen bromide are mixed in the dark. A number of products are formed, some in very small quantities. Which substance will not be present in the mixture of products? A 1-bromopropane B 2-bromopropane C 1,1-dibromopropane D 1,2-dibromopropane

Question

Which reagent could be used to distinguish between ethanal and propanal? A 2,4-dinitrophenylhydrazine B I2 / NaOH(aq) C K2Cr2O7 / H2SO4(aq) D Tollens’ reagent

Question

The diagram shows that a carboxylic acid P may be formed from X, Y or Z. alcohol aldehyde X Y carboxylic acid P nitrile Z Which row is correct? the change in Mr alcohol X is is greatest for A primary Y to P B primary Z to P C secondary Y to P D secondary Z to P

Question

One molecule of compound R is shown. compound R H H H O H C C C O C H H H H What is the name of compound R and how does its boiling point compare with that of butanoic acid? name of R boiling point of R A methyl propanoate higher than butanoic acid B methyl propanoate lower than butanoic acid C propyl methanoate higher than butanoic acid D propyl methanoate lower than butanoic acid

Question

The diagram shows the infra-red spectrum of Q. 100 transmittance 50 0 4000 3000 2000 1500 1000 500 wavenumber / cm–1 What could be Q? A butan-1-ol B butanoic acid C butanone D 3-hydroxybutanal 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

When O2 reacts with H2S the products are SO2 and H2O. Mixture Y contains an equal number of the two molecules shown, and no other molecules. 16 18 1 32 1 8O = 8O 1H – 16 S – 1H Which statements about Y are correct? 1 The average Mr in Y is 34. 2 If some oxygen molecules are removed from Y, the average Mr of the mixture remains the same. 3 When mixture Y is ignited, some H2S remains unreacted.

Question

Which statements about an atom of 99Tc are correct? 1 It has 13 fewer protons than neutrons. 2 It forms 99Tc2+ which has 45 electrons. 3 It has 56 nucleons.

Question

In which reactions are nitrogen atoms reduced? 1 2NO2 → N2 + 2O2 2 4NO2 → 2N2O + 3O2 3 4NO2 + 6H2O → 4NH3 + 7O2

Question

The manufacture of ammonia from nitrogen and hydrogen is an important industrial process. Which of the following would leave the equilibrium constant, Kp, for the formation of ammonia unchanged? 1 addition of an iron catalyst 2 addition of ammonia 3 an increase in pressure

Question

Which reactions involving calcium and its compounds produce two gaseous products? 1 heating solid anhydrous calcium nitrate 2 heating solid anhydrous calcium carbonate 3 adding calcium metal to water

Question

A small quantity of hot, concentrated sulfuric acid is added separately to solid samples of potassium halides, KX. Which potassium halides react and produce a mixture of products that include a halogen, X2? 1 potassium iodide 2 potassium bromide 3 potassium chloride

Question

The diagram shows a compound used as a flame retardant. Br Br Br Br Br Br Which statements about this structure are correct? 1 The empirical formula is C2H3Br. 2 The C12 ring is not planar. 3 There are six chiral carbon atoms. 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

Halogenoalkanes can be hydrolysed using aqueous sodium hydroxide. Which compounds tend to be hydrolysed by an SN1 mechanism? 1 CH3CH2CCl (CH3)CH2CH3 2 CH3CH2CBr(CH3)CH2CH3 3 CH3CH2CH(CH3)CH2CH2Br

Question

In an organic synthesis, a 62% yield of product is achieved. Which conversions are consistent with this information? 1 74.00 g of butan-2-ol → 44.64 g of butanone 2 74.00 g of butan-1-ol → 54.56 g of butanoic acid 3 74.00 g of 2-methylpropan-1-ol → 54.56 g of 2-methylpropanoic acid

Question

An oxidising agent that can oxidise ethanal to ethanoic acid or ethanoate ions will also oxidise methanoic acid, HCO2H, to carbon dioxide and water. Which reagents, on heating, will react differently with HCO2H and CH3CO2H? 1 Na2CO3(aq) 2 Fehling’s reagent 3 dilute acidified KMnO4