2024 Prelims YIJC H2 Chem P1 (QP)

©YIJC [Turn over YISHUN INNOVA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME CG INDEX NO CHEMISTRY Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet Data Booklet 9729/01 13 September 2024 1 hour READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid/tape. Write your name and class on the Answer Sheet in the spaces provided unless this has been done for you. 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 15 printed pages and 1 blank page.

©YIJC [Turn over 2 1 A sample of calcium contains three naturally occurring isotopes, 40Ca, 42Ca and 44Ca. The sample is made up of 96.64% of 40Ca and the relative atomic mass of calcium in this sample is 40.11. What is the percentage of the isotope 42Ca in the sample? A 0.44% B 0.67% C 1.22% D 2.09% 2 Aluminium chloride dimerises to give Al2Cl6. Which statement about aluminium chloride and its dimer is correct? A AlCl3 has a high melting and boiling point due to strong electrostatic forces of attraction between Al3+ and Cl−. B Each aluminium atom is surrounded by four chlorine atoms in the dimer, Al2Cl6. C Some of the bond angles decrease while some remains the same when AlCl3 dimerises to form Al2Cl6. D The geometry around each aluminium atom in Al2Cl6 is trigonal planar. 3 The graph shows the behaviour of one mole of an ideal gas. Which of the following will produce the graph shown? y-axis x-axis condition A pV p at constant temperature B p V at constant temperature C p 1/V at constant temperature D T (in K) V at constant pressure x y

©YIJC [Turn over 3 4 Sodium, magnesium, aluminium, silicon and phosphorus are all elements in Period 3 of the Periodic Table. Three statements about the oxides and chlorides of these elements are given. Which statements are correct? 1 The ionically bonded oxides all react with dilute hydrochloric acid. 2 All metal chlorides produced neutral solutions when added to water. 3 The two most electronegative elements both form covalently bonded chlorides. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only 5 The table shows the trend in the stated properties from magnesium to barium in Group 2. Which row is correct? decomposition temperature of the carbonate reducing power A increases increases B increases decreases C decreases increases D decreases decreases 6 Use of the Data Booklet is relevant to this question. The element astatine, At, is in Group 17 of the Periodic Table. Which statements about At will be true? 1 It is a coloured solid at room temperature. 2 Its hydride is thermally more stable than the hydride of iodine. 3 It is more electronegative than iodine. A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 1 only

©YIJC [Turn over 4 7 When 30 cm3 of a hydrocarbon was burnt in excess oxygen, there was a contraction of 105 cm3. On treating the cooled resulting mixture with excess potassium hydroxide, a further contraction of 150 cm3 occurred. All volumes were measured at r.t.p. What is the formula of the hydrocarbon? A C3H6 B C3H8 C C5H10 D C5H12 8 Iron metal and VO2+ were reacted together in a 1 : 1 ratio until all the iron metal was oxidised to Fe2+ ions. What is the oxidation state of vanadium in the product? A +2 B +3 C +4 D +5 9 Use of the Data Booklet is relevant to this question. Butanal can be synthesised from propene, C3H6. CH3CH=CH2(g) + CO(g) + H2(g) ⇌ CH3CH2CH2CHO(g) What is the value of the enthalpy change of the reaction? A +47 kJ mol–1 B −47 kJ mol–1 C +137 kJ mol–1 D −137 kJ mol–1

©YIJC [Turn over 5 10 Ammonia gas and hydrogen chloride gas react to form ammonium chloride. NH3(g) + HCl(g) → NH4Cl(s) ΔHo = −176 kJ mol−1 The magnitude of standard entropy change of this reaction is 284 J K−1 mol−1. Which statements are correct? 1 ∆Go is −261 kJ mol−1 for the above reaction. 2 There is a decrease in disorder as the particles in NH4Cl are held close to each other in fixed positions. 3 The reaction becomes non-spontaneous at high temperature. A 1 only B 1 and 2 only C 2 only D 2 and 3 only 11 A first-order decomposition reaction is shown below. 2XY(g) → X2Y2(g) The half-life of the reaction was found to be 3.46 s. What is the time taken for X2Y2(g) to reach 99% of its final concentration? A 21.0 s B 22.0 s C 23.0 s D 24.0 s

©YIJC [Turn over 6 12 Nitric oxide, NO, reacts with oxygen to form nitrogen dioxide. 2NO(g) + O2(g) → 2NO2(g) The reaction is thought to involve the following steps. NO + O2 ⇌ NO3 (fast) NO3 + NO → NO2 + NO2 (slow) Which conclusions can be drawn from this information? 1 O2 is acting as a catalyst. 2 NO3 is an intermediate in this reaction. 3 The reaction is first order with respect to NO. 4 The reaction is first order with respect to O2. A 1 and 2 B 2 and 3 C 2 and 4 D 2, 3 and 4

©YIJC [Turn over 7 13 The graph below shows how the number of moles of CH 4 varies with temperature at two different pressures of P1 and P2 respectively for the following equilibrium. CO(g) + 3H2(g) ⇌ CH4(g) + H2O(g) Which statements are correct? 1 The forward reaction is exothermic. 2 The magnitude of P1 is greater than the magnitude of P2. 3 Adding catalyst increases the amount of CH4 formed. A 1 only B 2 only C 1 and 2 only D 1, 2 and 3 14 12.50 cm3 of 0.100 mol dm−3 sodium hydroxide was added to 25.0 cm3 of 0.100 mol dm−3 hydrochloric acid. What is the pH of the resulting solution? A 1.00 B 1.48 C 2.60 D 2.90 temperature number of moles of CH4 P2 P1

©YIJC [Turn over 8 15 What is a suitable indicator for the titration between 0.10 mol dm –3 nitric acid and 0.10 mol dm –3 aqueous ammonia? A bromothymol blue (pH range 6.0–7.6) B methyl orange (pH range 3.1–4.4) C phenolphthalein (pH range 8.3–10.0) D There is no suitable indicator 16 The ionic product of water, Kw, is affected by temperature. temperature / °C Kw / mol2 dm−6 0 1.0 × 10−15 50 5.5 × 10−14 Which statement describes what happens as the temperature of water is increased from 0 °C to 50 °C? A pH of water increases and [H+] = [OH−] B pH of water increases and [H+] < [OH−] C pH of water decreases and [H+] > [OH−] D pH of water decreases and [H+] = [OH−] 17 An aqueous solution containing both potassium chloride and potassium iodide is treated with an excess of aqueous silver nitrate. The precipitate formed is filtered off and washed with deionised water. The precipitate is then shaken with aqueous ammonia and filtered off again. Which ion is present in the final filtrate? A chloride B iodide C potassium D silver

©YIJC [Turn over 9 18 Which molecule contains a total of two sp hybridised atoms? A H2C=CH–CH=CH2 B HCC–CCH C H2C=CH2 D HCCCH3 19 Which row is correct? 2