2022 CJC H2 CHEM Prelim P1 QP FINAL COPY

1 9729/01 CJC JC2 Preliminary Examination 2022 CANDIDATE NAME CLASS 2T CHEMISTRY 9729/01 Paper 1 Multiple Choice 15 September 2022 1 hour Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, class and NRIC/FIN number on the Answer Sheet in the spaces provided. There are thirty questions on this paper. Answer all questions. For each question there are four possible answers A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the separate Answer Sheet. Read the instructions on the Answer Sheet very carefully. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done in this booklet. The use of an approved scientific calculator is expected, where appropriate. This document consists of 14 printed pages. Catholic Junior College JC 2 Preliminary Examinations Higher 2

2 9729/01 CJC JC2 Preliminary Examination 2022 + – R S T 1 Which statement about 27 g of Al is always correct? A It contains the same number of atoms as 1 12 g of 12C. B It contains the same number of atoms as 24 dm 3 of krypton gas at room temperature and pressure. C It contains the same number of hydrogen ions as 1 dm3 of 1 mol dm -3 aqueous sulfuric acid. D It contains the same number of atoms as 28 g of nitrogen gas. 2 The following are flight paths of charged particles as they pass through an electric field at the same speed. Which of the following correctly identifies X, Y and Z? 3 Use of the Data Booklet is relevant to this question. Species containing one or more unpaired electrons can be attracted by an external magnetic field and are said to be paramagnetic. Which of the following species is paramagnetic? 1 Cr3+ 2 Cu+ 3 Ni2+ A 3 B 1 and 2 C 1 and 3 D 1, 2 and 3 X Y Z A 14N‾ 16O2+ 28Si2+ B 14N‾ 14C+ 28Si4+ C 15O+ 14C+ 14N+ D 15O‾ 14C+ 28Si+ X Y Z

3 9729/01 CJC JC2 Preliminary Examination 2022 [Turn over 4 In which of the following sequences are the species quoted in order of decreasing boiling points? A RbCl, KCl B HF, HCl C K, Ca D CO, CO2 5 People drink beverages containing caffeine to relieve or prevent drowsiness and to improve cognitive performance. Caffeine Which statement about caffeine is true? A Caffeine molecule has a planar structure. B The  bond in C=C is formed by sideways overlap of 2p orbitals. C The nitrogen atom in caffeine, N1 is basic. D There are 16 sigma bonds in a caffeine molecule. 6 Which of the following substances conduct electricity due to delocalised electrons? 1 Graphite 2 Solid magnesium 3 Molten sodium chloride A 1 only B 1 and 2 only C 2 and 3 only D 1, 2 and 3

4 9729/01 CJC JC2 Preliminary Examination 2022 7 Which of the following statements is incorrect? A When methane gas is subjected to low pressure, it liquefies. B Tyre pressure readings are higher on a hot day. C The boiling point of water is lower than 100ºC at a higher altitude. D The density of an ideal gas at constant pressure is inversely proportional to the temperature. 8 For the oxides of Period 3 elements (Na to P), which property decreases from Na 2O to P4O10? A melting point B covalent character C pH when mixed with water D solubility in aqueous alkali 9 The following graph shows how a property of the elements in Period 3, from Na to P, or their compounds, varies with proton number. What property is shown by the graph? A ionisation energies of elements B melting point of element C pH of aqueous chloride D electrical conductivity of element 10 Use of Data Booklet is relevant to this question. The GOsolution and SOsolution for silver chloride, AgC l are +55.6 kJ mol –1 and +33.2 J mol–1 K–1 respectively. What is the standard enthalpy change (HO) when 287 g of AgC l is precipitated under the same conditions? A +65.5 kJ B −65.5 kJ C +131 kJ D −131 kJ 11 12 13 14 15 proton number

5 9729/01 CJC JC2 Preliminary Examination 2022 [Turn over 11 The rate equation for a reaction between A and B is given by: rate = k[A] Which of the following statements about the reaction is true? 1 A is involved in the rate−determining step in the reaction mechanism. 2 The rate constant, k, increases with increasing concentration of A. 3 A graph of rate against [A] gives a straight line that passes through the origin. A 1,2 and 3 B 1 and 3 only C 2 only D 1 only 12 What is the pH of the final solution when V cm3 of dilute nitric acid of pH 2.0 is mixed with V cm3 of dilute nitric acid of pH 4.0 followed by the addition of 2V cm3 of water? A 2.3 B 2.6 C 3.0 D 3.6 13 Compound K is a yellow viscous oil found in plants. It has the following structure. O CH3 CH2CH CH3 CH3 CCH2 CH3 (CH2CH2CHCH2)3H CH3 What is the total number of stereoisomers for compound K? A 4 B 8 C 16 D 32 14 In the free radical substitution reaction of methane, CH4, one of the side-products formed is ethane, CH3CH3, which is formed when two •CH3 radicals combine. Upon careful heating, a sample of butane, CH3CH2CH2CH3, reacted with chlorine gas in a free radical substitution reaction to give only mono-substituted products. How many possible organic side-products would be obtained in this reaction when the radicals produced combine with each other? A 2 B 3 C 4 D 5

6 9729/01 CJC JC2 Preliminary Examination 2022 15 The reaction between carbon dioxide and potassium hydroxide is exothermic. The proposed two–step mechanism of the reaction is shown below: Step 1: CO2(aq) + KOH(aq) → KHCO3(aq) Step 2: KHCO3(aq)+ KOH(aq) → K2CO3(aq) + H2O(l) Experiments were carried out to study the rate of the reaction above. Which of the following graphs most likely describes the energy profile of the reaction above? A B C D Experiment Number Initial concentration of CO2 / mol dm–3 Initial concentration of KOH / mol dm–3 Initial reaction rate / mol dm–3 s–1 1 0.2 0.2 0.0034 2 0.4 0.2 0.0068 3 0.2 0.1 0.0017 Energy Reaction Pathway Energy Reaction Pathway Energy Reaction Pathway Energy Reaction Pathway

7 9729/01 CJC JC2 Preliminary Examination 2022 [Turn over 16 Aqueous bromine can react with propene in the presence of concentrated potassium nitrate solution. Which of the following is the major product formed in the reaction? A CH3CHBrCH2ONO2 B CH3CHBrCH2Br C CH3CHBrCH2OH D CH3CH(ONO2)CH2Br 17 Which synthetic route is most likely to lead to the most successful synthesis of the following product from benzene? A nitration, bromination, alkylation, reduction B nitration, bromination, reduction, alkylation C nitration, alkylation, reduction, bromination D alkylation, bromination, nitration, reduction 18 A few drops of 1–chlorobutane, 1–bromobutane, 1–iodobutane were placed separately into three test–tubes each, containing 1.0 cm3 of aqueous silver nitrate at 60 oC. A hydrolysis reaction occurred. (X is the halogen atom) H2O + CH3CH2CH2CH2X + Ag+ → CH3CH2CH2CH2OH + AgX + H+ Which of the following would be the best explanation for the rate of the reaction? A The bond energy of C−X bond decreases from C−Cl to C−I. B The bond polarity of C−X bond decreases from C−Cl to C−I. C The electron deficiency of the carbon atom bonded to X decreases from C−Cl to C−I. D The solubility of AgX decreases from AgCl to AgI.

8 9729/01 CJC JC2 Preliminary Examination 2022 19 Concentrated ammonia was heated in a sealed tube with excess bromoethane. Which of the following product will not be formed? A C4H10N B C4H11