2024 TMJC H2 Chem Prelim P1 (QP)

___________________________________________________________________ H2 CHEMISTRY 9729/01 Paper 1 Multiple Choice 19 September 2024 1 hour Additional materials: Multiple Choice Answer Sheet Data Booklet _________________________________________________________________________ READ THESE INSTRUCTIONS FIRST Write in soft pencil. Write your name, class and register number on the Answer Sheet in the spaces provided. 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 use of the Answer Sheet very carefully. You are advised to fill in the Answer Sheet as you go along . No additional time will be given for the transfer of answers once the examination has ended. 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. Use of the Answer Sheet Ensure you have written your name, class register number and class on the Answer Sheet. Use a 2B pencil to shade your answers on the Answer Sheet; erase any mistakes cleanly. Multiple shaded answers to a question will not be accepted. For shading of class register number on the Answer Sheet, please follow the given examples: If your register number is 1, then shade 01 in the index number column. If your register number is 21, then shade 21 in the index number column. TAMPINES MERIDIAN JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATION

2 Tampines Meridian Junior College 2024 JC2 Preliminary Examination H2 Chemistry 1 Use of the Data Booklet is relevant to this question. A stream of gaseous Ca2+ 20 40 charged ions was passed through an electric field between two oppositely charged plates and the Ca2+ ions were deflected at an angle of +15.0°. Under the same electric field, a stream of unknown gaseous X3− ion was deflected at an angle of −29.0°. What is a possible atomic number of X? A 15 B 24 C 31 D 34 2 Which statements correctly describe an electron shell with the principal quantum shell number n = 2? 1 A total of 10 electrons can be accommodated in this shell. 2 An orbital from this shell must be dumb-bell in shape. 3 The energy level of the orbitals in this shell is higher than that in n = 1. A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 3 only 3 The table identifies the shape and polarity of four molecules. Which row is correct? molecule molecular shape polarity A bromine trifluoride bent polar B phosphorus trichloride trigonal pyramidal polar C sulfur dichloride linear non-polar D trifluoromethane tetrahedral non-polar

3 Tampines Meridian Junior College 2024 JC2 Preliminary Examination H2 Chemistry [Turn over 4 The table shows four species with their corresponding physical properties. Which species does not correspond to its description of physical properties? species physical properties A copper high melting point, conducts electricity when solid and when molten B silicon dioxide high melting point, does not conduct electricity in any state C aluminium bromide high melting point, conducts electricity when molten but not when solid D phosphorus pentachloride low melting point, does not conduct electricity in any state 5 Use of the Data Booklet is relevant to this question. Which of the following shows the correct trends when the melting points of the elements, Mg, Al, Si and P are plotted against their atomic radii? A B C D

4 Tampines Meridian Junior College 2024 JC2 Preliminary Examination H2 Chemistry 6 Which statement is correct about the halogens (X2) chlorine, bromine and iodine as well as their corresponding hydrogen halides (HX)? A The colour intensity of the halogens decreases from Cl2 to I2. B The oxidising power of the halogens decreases from Cl2 to I2. C The thermal stability of HX increases from HCl to HI. D The volatility of HX increases from HCl to HI. 7 Which graph correctly represents the relationship between ( 1 pV) and pressure for an ideal gas at constant temperature? 8 1 dm3 of a gaseous hydrocarbon was mixed with excess oxygen. When the mixture undergoes complete combustion, the volume contracted by 2 dm3. When the resultant mixture was passed through concentrated sodium hydroxide, the gas volume further decreased by 2 dm3. All volumes were measured at room temperature and pressure. What is the empirical formula of the hydrocarbon? A CH B CH2 C C2H3 D C3H4 1 pV p 1 pV p 1 pV p 1 pV p A B C D

5 Tampines Meridian Junior College 2024 JC2 Preliminary Examination H2 Chemistry [Turn over 9 Substances X and Y react to form product Z. 2X + Y → 2Z The reaction was studied and the following data were obtained. experiment [X] / mol dm−3 [Y] / mol dm−3 initial rate / mol dm−3 min−1 1 0.10 0.10 0.020 2 0.20 0.10 0.080 3 0.15 0.23 0.045 What is the order of reaction with respect to X and Y? A First order with respect to X and zero order with respect to Y. B Second order with respect to X and first order with respect to Y. C First order with respect to X and first order with respect to Y. D Second order with respect to X and zero order with respect to Y. 10 The following enthalpy changes of the following substances are provided. / kJ mol–1 standard enthalpy change of combustion of graphite –394 standard enthalpy change of formation of water –286 standard enthalpy change of formation of liquid ethanol –277 What is the standard enthalpy change of combustion of liquid ethanol? A –403 kJ mol–1 B –957 kJ mol–1 C –1369 kJ mol–1 D –1865 kJ mol–1 11 Which processes result in an increase in entropy? 1 crystallisation of salt from its saturated solution 2 condensation of steam to water 3 combustion of hydrogen gas 4 mixing of two miscible liquids A 1 and 2 only B 2 and 3 only C 3 and 4 only D 4 only

6 Tampines Meridian Junior College 2024 JC2 Preliminary Examination H2 Chemistry 12 Consider the following equilibrium reaction: H2(g) + Cl2(g) ⇌ 2HCl(g) H < 0 Which of the following changes will decrease the equilibrium yield of HCl? A adding more H2(g) B adding a suitable catalyst C decreasing the volume of the system D increasing the temperature 13 Which of the following is not an acid-conjugate base pair? A HCl and NaCl B Na2HPO4 and H3PO4 C H2O2 and HO2− D 14 Values of ionic product, Kw, for water at different temperatures are given below. temperature / ºC 0 25 100 Kw / mol2 dm−6 1.1 x 10−15 1.0 x 10−14 5.1 x 10−13 Which statement is true? A pOH + pKw = 14 at 0 ºC. B At temperatures higher than 25 ºC, [H+] > [OH−]. C The pH of water is expected to be 6.1 at 100 ºC. D The dissociation of water is an exothermic process. 15 What is the largest mass of sodium ethanedioate, Na 2C2O4 (Mr = 134.0) that can be added to 25 cm 3 of 1.1 × 10 ‒3 mol dm‒3 solution of calcium nitrate, Ca(NO 3)2 before a precipitate forms? [Ksp of CaC2O4 = 2.50 × 10‒9 mol2 dm‒6 ] A 2.5 × 10‒5 g B 7.6 × 10‒6 g C 7.5 × 10‒9 g D 2.5 × 10‒9 g

7 Tampines Meridian Junior College 2024 JC2 Preliminary Examination H2 Chemistry [Turn over 16 Wh