JJC H2 CHEM P1

JURONG JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 2 CHEMISTRY 9746/01 Paper 1 Multiple Choice 28 August 2009 1 hour Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, class and shade your exam number on the Answer Sheet in the spaces provided. There are forty 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 you 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. A Data Booklet is provided. Do not write anything on the Data Booklet. This document consists of 16 printed pages and 1 blank page [Turn over

SECTION A (30 MARKS) For each question there are four possible answers, A, B, C and D . Choose the one you consider to be correct. 1. 0.904 g of Pb(C 2H3O2)2.dH2O was weighed and heated to drive off the water of crystallisation. The mass of the residue obtained was 0.774 g. Calculate the value of d in Pb(C2H3O2)2.dH2O. A 1 B 2 C 3 D 6 2. Tin(IV) iodide can be prepared by refluxing 0.04 mol of tin with 0.03 mol of iodine (I 2) dissolved in 50 cm3 of tetrachloromethane (boiling point 77C). Sn + 2I2 → SnI4 Orange crystals of the product are obtained by filtering the hot reaction mixture and then cooling the filtrate. What would indicate that the reaction was complete? A The boiling point of the mixture is 77C. B No tin remains in the reaction flask. C Crystals begin to be deposited from the boiling solvent. D No more purple vapour is seen in the reaction vessel. 3. It was believed that the bombardment of polonium atoms, Po, with atoms of an isotope of a Group III element, X, may bring about a new element with proton number 115 via the following reaction. Suggest the identity of X. Po + X  [new element] + 5 neutrons. 285 115 A Aluminium B Gallium C Indium D Thallium 209 84 Page 2 of 16

4. Two vessels containing 4 dm 3 of argon and 0.01m 3 of water vapour respectively at 150°C and 101 kPa were connected together. The connected vessels were allowed to cool to room temperature. What was the final pressure in the connected vessel? A 4.18 kPa B 16.8 kPa C 20.3 kPa D 71.2 kPa 5. The structure of propenoic acid is shown below. Which of the following statements is incorrect about the structure? A There are 8 σ bonds and 2 π bonds in the molecule. B All the carbon atoms lie on the same plane. C Bond angle x and y are 120º and 105° respectively D All the carbon atoms are sp 3 hybridised. x H C H C H C O O y H BF •CH6. 3 3OH is a reagent used to form methyl esters from compounds containing acyl groups. In the diagrams below, x, • and סrepresent electrons from B, F and O, respectively. Which tetrahedral structure illustrates the electron pairs around the boron atom? A B C D F x • F •x F •• F •x B FF O x x • x •x CH3 H B FF O סס • x •x CH3 H B FF O xס x x • • CH3 H B FF O x • xס x• CH3 H Page 3 of 16

7. Strontium hydride is an ionic compound. The standard enthalpy changes, ΔH1 and ΔH2 are known. Sr(s)  Sr2+(g) + 2e– ------------------- ΔH1 H 2(g) + 2e–  2H–(g) ------------------- ΔH2 What additional data is needed to determine the lattice energy of strontium hydride? A The first ionisation energy of hydrogen. B The standard enthalpy change of atomisation of hydrogen. C The standard enthalpy change of atomisation of strontium. D The standard enthalpy change of formation of strontium hydride. 8. When 13.1 g ( 0.2 mol) of zinc dust was added to 250 cm 3 of 1.0 mol dm -3 aqueous copper(II) sulphate (an excess), the temperature of the solution rose by 15 °C. The specific heat capacity of the solution is 4.20 J g-1 K-1. What is the enthalpy change for the reaction Cu2+ + Zn  Zn2+ + Cu ? A –78.8 kJ mol-1 B –4.13 kJ mol-1 C +4.13kJ mol-1 D +78.8 kJ mol-1 9. Given that A2 (g) + 4C (g) ⇌ 2AC2 (g) Kc = 4.8 (numerical value) it follows that, for the reaction, AC 2 (g) ⇌ ½ A2 (g) + 2C (g) Kc = X (numerical value) X would be A 8 . 4 1 B 4 . 2 1 C 2.4 D 8 . 4 1 Page 4 of 16

10. What is the resultant pH when equal volumes of a solution of pH 1.0 and pH 3.0 are added together? A 1.3 B 1.5 C 2.0 D 2.5 11. A solution, saturated with Ca(OH) 2 and CaSO 4, has a pH of 12.3. What is the concentration, in mol dm─3, of SO4 2─ ions in the solution? (K sp value of Ca(OH)2 = 4.0 x 10─5, Ksp value of CaSO4 = 2.5 x 10─5) A 1.25 x 10─2 B 2.50 x 10─2 C 1.25 x 10─4 D 2.50 x 10─4 12. When a dilute sulfate solution of a metal J was electrolysed, the metal J and a diatomic gas K are produced at the cathode and anode respectively in the molar ratio 2:1. In another experiment, the same quantity of electricity is used to electrolyse a saturated sodium chloride solution and a gas L is evolved at the anode. What is the molar ratio of J:K:L ? A 4 : 2 : 1 B 4 : 2 : 3 C 2 : 1 : 1 D 2 : 1 : 2 13. Which curve is obtained if the rate of reaction is plotted against time for an autocatalytic reaction (i.e. a reaction in which one of the products catalyses the reaction)? A A B C D rate rate 0 0 time 0 time 0 rate rate time time Page 5 of 16

14. The graph below shows the variation in boiling point for 8 consecutive elements in the Periodic Table, all with atomic number ≤ 20. What can be deduced from the above? A Element A forms a chloride which exists as a dimer in the vapour phrase. B Element D is in the same group as nitrogen in the Periodic Table. C Element F exists as diatomic molecules. D Element G forms an oxide which is acidic in aqueous solution. H ● ● G ● F ● E ● D ● C ● B ● A Boiling point / C Atomic No. 15. P and Q are hydroxy compounds of the elements X and Y respectively. X and Y are in the same period of the Periodic Table. P gives an aqueous solution of pH < 7. Q gives an aqueous solution which is strongly alkaline. Which one of the following statements is true? A The atomic radius of X is greater than Y. B The first ionsation energy of X is smaller than Y. C The electronegativity of X is greater than Y. D The atomic number of X is smaller than Y. Page 6 of 16

16. How would the magnitude of the following vary down Group II? (i) the standard electrode potential of M 2+(aq)/ M(s) electrode, Eo, (ii) the lattice energy of the oxide, H latt, (iii) the standard enthalpy change of hydration of M 2+(g), H hyd. Eo M2+/ M H latt of MO(s) H hyd of M2+(g) A increases decreases decreases B decreases decreases increases C increases increases decreases D increases increases increases o o o o 17. Which statement is true about the chemistry of sodium bromide? A It is a much weaker reducing agent than sodium chloride. B It reacts with iron(III) chloride solution to form a pale green solution. C It liberates a red-brown gas on warming with concentrated sulphuric acid. D It is formed together with sodium bromate(I) when bromine is bubbled into hot concentrated sodium hydroxide. 18. Transition metals like platinum and rhodium are found in catalytic converters fitted into cars. Which of the following statements best explains