2024 RI Prelim H2 Chem Paper 1 QP Final

© Raffles Institution 2024 9729/01/S/24 [Turn Over RAFFLES INSTITUTION 2024 YEAR 6 PRELIMINARY EXAMINATION Higher 2 CHEMISTRY 9729/01 Paper 1 Multiple Choice 19 September 2024 1 hour Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Do not open this question booklet until you are told to do so. Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, class and index number in the spaces provided on the Answer Sheet. There are thirty questions in 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 the question booklet. The use of an approved scientific calculator is expected, where appropriate. This document consists of 15 printed pages and 1 blank page.

© Raffles Institution 2024 9729/01/S/24 [Turn Over 2 1 Use of the Data Booklet is relevant to this question. How many molecules are present in 1 cm3 of methane gas under room temperature and pressure? A 6.02 × 1023 24000 B 6.02 × 1023 22400 C 22400 6.02 × 1023 D 24000 6.02 × 1023 2 When 20 cm3 of a gaseous hydrocarbon was completely burnt in 130 cm 3 of oxygen in an enclosed vessel, the volume of gas remaining after the reaction was 100 cm 3. This volume was decreased to 40 cm3 under the same conditions when the resulting mixture was passed through aqueous sodium hydroxide. All gas volumes are measured at room temperature and pressure. What is the formula of the hydrocarbon? A C2H2 B C3H6 C C3H8 D C4H10 3 What do the ions 18O2− and 19F− have in common? A They have more electrons than neutrons. B They have 10 neutrons in their nuclei. C They have an outer electronic configuration of 3s2 3p6. D They contain the same number of nucleons in their nuclei. 4 In beta−minus decay, a neutron in the nucleus of an atom is converted into a proton and a beta particle (electron). This increases the atomic number by 1 while the mass number remains unchanged. Thorium−234, Th90 234 , undergoes beta−minus decay. What is the resulting species after the decay process? A Ac89 234 B Pa91 233 + C Pa91 234 D Th90 235 −

© Raffles Institution 2024 9729/01/S/24 [Turn Over 3 5 Water has a higher boiling point than hydrogen fluoride. What is the major reason for this? A The O−H bond in water is stronger than the F−H bond in hydrogen fluoride. B A water molecule contains more electrons than a hydrogen fluoride molecule. C On average, there are more hydrogen bonds between water molecules than there are between hydrogen fluoride molecules. D A hydrogen fluoride molecule is more polar than a water molecule. 6 The diagram shows the structure of part of a crystal of ice. Which statement is correct? A The open structure of ice causes ice to be denser than water. B The hydrogen bonds are stronger than the O−H covalent bonds. C Two electrons from each oxygen are involved in forming hydrogen bonds. D Each oxygen atom is tetrahedrally bonded to four hydrogen atoms through covalent or hydrogen bonds.

© Raffles Institution 2024 9729/01/S/24 [Turn Over 4 7 Compound E, C3H2Cl2, is non-cyclic. Which statements are correct for E and all its non-cyclic isomers? 1 There are 6 σ and 2 π bonds present. 2 The optically active isomers each contain a chiral carbon. 3 There is a total of five non-cyclic isomers, including stereoisomers. A 1 and 2 B 1 and 3 C 2 and 3 D 1 only 8 Which graph is correct for a fixed mass of an ideal gas? A B constant V constant T C D constant T constant V 9 Which row correctly describes the general trends from sodium to chlorine across Period 3 of the Periodic Table? atomic radius electronegativity 1st ionisation energy A increases decreases decreases B decreases increases decreases C decreases increases increases D increases increases increases p T / oC p pV 0 0 V p p T p 0 0

© Raffles Institution 2024 9729/01/S/24 [Turn Over 5 10 Elements L and M are in Period 3 of the Periodic Table. The oxide of L dissolves sparingly in water. The pH of the solution of the chloride of L is higher than that of the chloride of M. Which row correctly shows the identities of L and M? L M A Mg Al B Mg Na C Na Si D Na S 11 Which property of X2 increases down the group for X = Cl, Br or I? A volatility B bond length C bond energy D oxidising power 12 The standard enthalpy change of th e following reaction, ∆Hr, can be calculated using the data in the table. 2NO(g) + O2(g) → N2O4(g) equation ∆H / kJ mol–1 1 2 N2(g) + 1 2 O2(g) → NO(g) +91 1 2 N2(g) + O2(g) → NO2(g) +34 2NO2(g) → N2O4(g) –58 What is the value of ∆Hr? A –172 kJ mol–1 B –115 kJ mol–1 C –56 kJ mol–1 D –1 kJ mol–1 ∆Hr

© Raffles Institution 2024 9729/01/S/24 [Turn Over 6 13 Hydrochloric acid can react with sodium and sodium oxide to give different products. Which statement is correct? A ∆H1 + ∆H2 is always positive. B ∆H3 + ∆H4 is always positive. C ∆H3 – ∆H4 – ∆H1 is always negative. D ∆H2 + ∆H3 – ∆H1 is always negative. 14 The following reaction is catalysed by an enzyme. CH3CHO + 2[H] → CH3CH2OH The graph shows how the rate of the reaction varies with [CH3CHO]. Which statement is correct when [CH3CHO] = c? A There are no more enzyme active sites available. B The order of reaction with respect to [CH3CHO] is 1. C As more CH3CH2OH is produced, the reaction slows down. D All the CH3CHO has been used up and the reaction stops. 2Na(s) + 2HCl(aq) + 1 2O2(g) 2NaCl(aq) + H2(g) + 1 2O2(g) Na2O(s) + 2HCl(aq) ∆H2 ∆H1 2NaCl(aq) + H2O(l) ∆H4 ∆H3 [CH3CHO] rate c

© Raffles Institution 2024 9729/01/S/24 [Turn Over 7 15 X(g) is placed in a sealed vessel and allowed to reach equilibrium at constant temperature. X(g) ⇌ Y(g) Under the same conditions, which statements are correct? 1 Given that X and Y behave as ideal gases, Kc = Kp. 2 PY PX at equilibrium is the same if Y(g) is used initially instead of X(g). 3 Adding more X(g) causes the partial pressures of both gases to be higher at the new equilibrium. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only 16 20.0 cm3 of 0.100 mol dm−3 of dilute nitric acid was titrated against 0.100 mol dm−3 of aqueous ammonia. Which volume of aqueous ammonia is required to produce a buffer with maximum buffering capacity? A 10.0 cm3 B 20.0 cm3 C 30.0 cm3 D 40.0 cm3 17 A 1.00 mol dm−3 solution of CH3COO− was prepared at 50 °C. Ka for ethanoic acid = 1.63 × 10−5 mol dm−3 and pKw = 13.3 at 50 °C. What is the pH of this solution at 50 °C? A 4.26 B 9.04 C 9.39 D 9.74 18 Which substance will cause the formation of a precipitate when added to a saturated solution of magnesium carbonate? A NaCl(s) B H2O(l) C K2CO3(s) D HCl(aq)

© Raffles Institution 2024 9729/01/S/24 [Turn Over 8 19 Use of the Data Booklet is relevant to this question. Which row gives the standard cell potential on the voltmeter and the correct direction of electron flow in the connecting wire? Ecell / V direction of flow A +0.56 F to G B +0.56 G to F C −0.56 F to G D −0.56 G to F 20 The process of coating aluminium objects with an inert layer via electrolysis is called anodising. The set-up used for anodising aluminium is