CJC H2 CHEM P1 QP Prelim

CHE Paper Additio READ Write yo Write in Do not u There a r possible Choose Sheet. Read t h Each co Any roug The use CAT JC2 P High EMISTR 1 Multiple onal Materi THESE IN our name and soft pencil. use staples, p re forty ques e answers A, the one you he instructio orrect answer gh working s e of an appro This d THOLIC J PRELIMIN er 2 RY e Choice als: Multi p Data B NSTRUCTI d HT group o paper clips, stions on this B, C and D. u consider co ons on the A r will score o should be do ved scientific document JUNIOR C NARY EXA ple Choice Booklet IONS FIRS on the Answe highlighters, s paper. Ans . orrect and rec Answer Shee ne mark. A m ne in this bo c calculator i consists of 1 COLLEG AMINATIO Answer S ST er Sheet in th glue or corre swer all ques cord your ch et very care mark will not oklet. is expected, f 16 printed GE NS Wed heet he spaces pr ection fluid. stions. For ea oice in soft fully. be deducted where appro d pages an nesday 2 rovided. ach question pencil on the d for a wrong opriate. nd 0 blank [Turn 96 Septembe n there are fo e separate A g answer. page. n over 647/01 er 2015 1 hour our Answer

2 9647/01/CJC JC2 Preliminary Exam 2015 Section A 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 in soft pencil on the separate Answer Sheet provided. 1 When 20 cm 3 of a gaseous hydrocarbon was completely burnt in 130 cm 3 of oxygen, the volume of gas remaining after the reaction was 100 cm 3. This volume was decreased to 40 cm 3 when the resulting mixture was passed through aqueous sodium hydroxide. All measurements were made at room temperature and pressure. What is the formula of this hydrocarbon? A C2H2 B C 3H6 C C3H8 D C4H10 2 Consider the following half-equations: C2O4 2– → 2CO2 + 2e– Fe2+ → Fe3+ + e– MnO4 – + 8H+ + 5e– → Mn2+ + 4H2O What volume of 0.01 mol dm –3 potassium manganate( VII) is required to oxidise completely 25.0 cm3 of an acidified solution of 0.01 mol dm–3 FeC2O4? A 10 cm3 B 15 cm 3 C 25 cm3 D 42 cm3 3 X and Y are elements with atomic numbers between 6 and 15. Their first seven ionisation energies in kJ mol–1 are shown below. X 580 1800 2700 11600 14800 18400 23300 Y 1310 3400 5300 7500 11300 13300 71300 Which of the following best describes the compound formed between X and Y? A basic B acidic C neutral D amphoteric

4 W (i) (ii 5 W A B C D 6 W an ( A C Which pair o ) The firs t second c i) The sec o A B C D Which of the Tetrach easily. CHCl3 CHF3. Hydrog perma n Each hy betwee Which of th e n ideal gas?  = density A C  0 0 V 9 f compound t compoun compound a ond compo first com BC CF HC PH following s hloromethan has a high e en chlorid e nent dipole f ydrogen bo n HF molec e following d ? of the gas, constant constant T 9647/01/CJC ds fits the fo d has a l a and, und is more mpound l3 F4 N H3 statements r ne is a vol a er boiling p e is solubl e forces of att nd formed b cules. diagrams d T = temper t T p 1/p T 3 JC2 Prelimina ollowing des arger bond e polar than regarding c atile liquid point than C e in water traction with between H2 does not de rature meas ary Exam 201 scriptions? angle abo n the first co second c S Xe Be N ovalent com because t h CHF3 becau because it h water mol 2O molecule escribe the sured in K) B D pV 0 0 p 5 ut the cen t ompound. compound SO2 eF4 eCl2 NH3 mpounds is he C–C l b o se it has m can form lecules. es is strong behaviour constant constant [Turn tral atom t true? ond can b e more electro permanent er than that of a fixed t T  V T n over than the e broken ons than t dipole- t formed mass of

4 9647/01/CJC JC2 Preliminary Exam 2015 7 A nitrogen–hydrogen mixture, initially in the mole ratio of 1:3, reached equilibrium with ammonia when 50 % of the nitrogen had reacted. The total final pressure was p. N2(g) + 3H2(g) ⇌ 2NH3 (g) What was the partial pressure of ammonia in the equilibrium mixture? A p 6 B p 4 C p 3 D p 2 8 The heat liberated in the neutralisation given below is -57 kJ mol–1. HNO3(aq) + NaOH(aq) → NaNO3(aq) + H2O(l) By using this information, what is the most likely value for the heat liberated in the following neutralisation? H 2SO4 (aq) + 2NaOH(aq) → Na2SO4(aq) + 2H2O(l) A -57 kJ mol –1 B -86 kJ mol–1 C -114 kJ mol–1 D -228 kJ mol –1 9 The value of ionic product Kw, at 35oC is 2.04 x 10-14. What is correct for pure water at 35 oC? A pH < 7 B pH = 7 C [H +] < [OH-] D [OH -] = 1.02 x 10-14 mol dm-3 10 A solution of 20.0 cm 3 of 0.10 mol dm –3 sulfuric acid was titrated with 0.10 mol dm–3 ammonia. Which statement regarding the titration is correct? A The equivalence point is at pH 7. B The initial pH of the solution is 1. C 20.0 cm3 of ammonia is required for titration for equivalence point to be reached. D 80.0 cm3 of ammonia is required for titration for maximum buffer capacity to be reached.

5 9647/01/CJC JC2 Preliminary Exam 2015 [Turn over 11 Use of the Data Booklet is relevant to this question. Soda is slightly acidic due to dissolved carbon dioxide. By considering the relevant E o values, which metal will not be dissolved by the soda? A V B Ag C Mg D Sn 12 15.7 g of the metal gadolinium (Gd) was deposited in electrolysis by a current of 5 A for 96.5 minutes. What is the formula of gadolinium ions? [A r of Gd = 157] A Gd+ B Gd2+ C Gd3+ D Gd4+ 13 Barium is the final product formed by a series of changes in which the rate-determining step is the radioactive decay of caesium-137. This radioactive decay is a first-order reaction with a half-life of 30 years. How long would it take for a rock sample, originally barium-free, to contain a molar proportion of caesium-137 to barium of 1:7? A 15 years B 30 years C 60 years D 90 years

6 9647/01/CJC JC2 Preliminary Exam 2015 14 The reaction between chlorite ions, ClO2 –, and iodide ions, I–, in acid solution may be represented by the following equation. ClO2 – + 4I– + 4 H+→ 2I2 + Cl– + H2O The rate-time graph for this reaction is as shown below. What does the shape of the graph suggest about this reaction? A The reaction is endothermic. B The reaction is overall first order. C The reaction produces its own catalyst. D The reaction rate is independent of iodide ions. 15 The graph below shows the variation in melting points for eight consecutive elements, A - H, in the Periodic Table, all with atomic number between 10 and 20. What can be deduced from the graph? A The chloride of element C fumes in moist air. B Element F exists as a diatomic molecule. C The oxide of element B dissolves in water to give an acidic solution. D Element A has a higher first ionisation energy than the element preceding it. melting point atomic number A B C D E F rate time G H

7 9647/01/CJC JC2 Preliminary Exam 2015 [Turn over 16 Which of the following statements about the Group II elements (from Mg to Ba) or its compounds is incorrect? A The ease of thermal decomposition of Group II nitrates decreases down the group. B The reactivity of the elements with chlorine gas increases down the group. C The melting point of the oxides increases down the group. D The volume of gases formed per gram of carbonate decomposed decreases down the group. 17 Some properties of two salts, M and N, are given below. When salt M was mixed with concentrated sulfuric acid, a colourless gas was produced. An aqueous solution of this colourless gas gave a white precipitate with silver nitrate. The precipitate readily dissolved in aqueous ammonia. When salt N was h