RJC_Chemistry H1 P1 with Ans Prelim

RAFFLES JUNIOR COLLEGE PRELIMINARY EXAMINATION 2008 HIGHER 1 CHEMISTRY 8872/01 Paper 1 Multiple Choice 19 September 2008 50 minutes Additional Materials: Mult iple 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, highlighters, glue or correction fluid. Write your name, Candidate 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 to be correct and record your choice with a soft pencil on the separate Answer Sheet. Read the instructions on the Answer Sheet very carefully. Each correct answer will score one mark. A ma rk will not be deducted for a wrong answer. Any rough working should be done in this booklet. This question booklet consists of 9 printed pages. -1-

Section A For each question there are four possible answers, A, B, C, and D. Choose the one you consider to be correct. 1 An aqueous solution c ontaining 1 mole of S 2O3 2− ions reduces 4 moles of bromine molecules. What is the sulphur-containing product of this reaction? A H2S B SO2 C SO4 2− D S4O6 2− 2 The use of the Data Booklet is relevant to this question. The pH of pure water is 7.0 at 298 K. Whic h of the following quantities is equal to the number of ions in 1 dm3 of pure water at 298 K? A The number of neutrons in 8.0 x 10 –7 g of deuterium gas, D2 (D = 2H). B The number of atoms in 4.48 x 10–6 dm3 of Cl2 at s.t.p. C The number of molecules in 1.44 x 10–4 g of Buckministerfullerene, C60. D The number of anions in 1.0 x10–14 dm3 of 1.0 mol dm–3 K2C2O4(aq). 3 Self-igniting flares contain Mg 3P2. With water, this produces diphosphane, P2H4, which is spontaneously flammable in air. Which equation that includes the formation of diphosphane is balanced? A Mg 3P2 + 6H2O ⎯→ 3Mg(OH)2 + P2H4 B Mg 3P2 + 6H2O ⎯→ 3Mg(OH)2 + P2H4 + H2 C 2Mg 3P2 + 12H2O ⎯→ 6Mg(OH)2 + P2H4 + 2PH3 D 2Mg 3P2 + 12H2O ⎯→ 6Mg(OH)2 + 3P2H4 4 The table below contains incomp lete information about the two ions X and Y. Ion Mass number Atomic number Number of neutrons Number of electrons Charge of ion X 59 27 p q +2 Y 79 r 45 36 s Which of the following s hows the missing numbers (p, q, r and s) in the table above? p q r s A 29 27 34 +2 B 32 27 34 –2 C 59 25 36 +2 D 32 25 34 –2 -2-

5 An element Z has a second ionisation energy hi gher than that of the element preceding it and the element after it in the Periodic Table. What is the atomic number of Z? A 10 B 13 C 14 D 15 6 Which of the