SRJC H2 CHEM P1 QP

SERANGOON JUNIOR COLLEGE General Certificate of Education Advanced Level Higher 2 Candidate Name Class CHEMISTRY 9647/01 Preliminary Examination 29 August 2014 Paper 1 Multiple Choice 1 hour Additional Materials: Data Booklet Optical Mark Sheet (OMS) READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, FIN/NRIC number and class on the OMS in the spaces provided. Shade correctly FIN/NRIC number and your class. Eg. If your NRIC is S9306660Z, shade S9306660Z for the item “index number”. There are forty 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 using a soft pencil on the separate OMS. 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 question paper. This document consists of 22 printed pages and 2 blank pages.

2 SRJC 9647/01/PRELIM/2014 Turn Over] Section A For each question there are four possible answers, A, B, C and D. Choose the one you consider to be correct. 1 The hydrolysis of S2Cl2 proceeds by two reactions. Reaction 1 S2Cl2 + 2H2O H2S + SO2 + 2HCl Reaction 2 2H2S + SO2 8 3 S8 + 2H2O Which of the following correctly describe the reactions? A A weakly acidic solution is formed in Reaction 1. B Reverse disproportionation occurs in Reaction 2. C The oxidation state of chlorine and oxygen changes in both reactions. D The products of Reaction 1 require 2 mol of NaOH for complete neutralisation. 2 Sodium carbonate peroxyhydrate with the formula (Na2CO3)x y H2O2 is used in eco-friendly cleaning products and as a laboratory source of anhydrous hydrogen peroxide. When 20.0 cm 3 of 0.100 mol dm –3 sodium carbonate peroxyhydrate is titrated with 0.200 mol dm –3 acidified KMnO4, it requires 12.0 cm 3 of acidified KMnO 4 before the first pink colour appears. 2MnO4 – + 6H+ + 5H2O2 2Mn2+ + 8H2O + 5O2 When an identical sample is acidified, it releases 96.0 cm 3 of carbon dioxide at room conditions. What is the ratio of x:y ? A 1 : 3 B 2 : 3 C 2 : 1 D 3 : 1

3 SRJC 9647/01/PRELIM/2014 Turn Over] 3 The successive ionisation energies, in kJ mol -1, of an element E are given below. 578 1820 2750 11600 14800 18400 Which of the following could be the electronic configuration of the outermost shell in E? A ns2 B ns2 np1 C ns2 np2 D ns2 np3 4 The diagram represents the melting points of four consecutive elem ents in the third period of the Periodic Table. The sketches below represent another two properties of the elements. Which of the following represents the properties F and G? property F property G A third ionisation energy electronegativity B number of valence electrons boiling point C ionic radius effective nuclear charge D electrical conductivity atomic radius     proton number 0 melting point / K     proton number 0 property F     proton number 0 property G

4 SRJC 9647/01/PRELIM/2014 Turn Over] 5 Two identical bulbs at the same temperature contain ideal gases J and K separately. The density of gas J is twice that of gas K and the molecular mass of gas J is half that of gas K. What is the ratio of the pressure of gas J to that of gas K? A 1 : 2 B 1 : 1 C 2 : 1 D 4 : 1 6 Which of the following statements about an ideal gas are correct? A One mole of any ideal gas occupies the same volume under the same conditions of temperature and pressure. B The density of an ideal gas at constant pressure is directly proportional to the temperature. C The volume of a given mass of an ideal gas is doubled when its temperature is raised from 25 °C to 50 °C. D The temperature of a given mass of an ideal gas is doubled when its volume is raised from 0.05 cm3 to 0.1 dm3.

5 SRJC 9647/01/PRELIM/2014 Turn Over] 7 The type of bonding between two elements can be rationalised and even predicted using a van Arkel triangle. The triangle is based on electronegativity values. Difference in electronegativity is plotted along the y –axis and average electronegativity is plotted along the x–axis. What is the type of bonding present at each of these bonding extremes, labelled L, M and N on the triangle? L M N A covalent metallic ionic B metallic covalent ionic C covalent ionic metallic D ionic covalent metallic 8 Lead is the final product formed by a series of changes in which the rate–determining stage is the radioactive decay of uranium –238. This radioactive decay is a first–order reaction with a half–life of 4.5 x 109 years. What would be the age of a rock sample, originally lead–free, in which the molar proportion of uranium to lead is now 1:31? A 2.25 x 1010 years B 2.70 x 1010 years C 3.15 x 1010 years D 3.60 x 1010 years L M N average electronegativity difference in electronegativity 

6 SRJC 9647/01/PRELIM/2014 Turn Over] 9 When 0.1 mol of bismuth chloride is added to 2 dm 3 of water, it reacts to form 0.02 mol of white precipitate of bismuth oxychloride and a solution of hydrochloric acid: BiCl3 (aq) + H2O (l) BiOCl (s) + 2HCl (aq) What is the correct expression for the equilibrium constant Kc? A 08.0 )02.02( 2x B 08.0 )02.02)(02.0( 2x C 2 08.0 )2 02.02( 2x D 2 08.0 )2 02.02)(2 02.0( 2x 10 What is the pH of the resultant solution when 100 cm 3 of 0.10 mol dm −3 of aqueous NH 3 and 80 cm 3 of 0.15 mol dm −3 aqueous NH 4Cl are mixed at 25 oC? (pKb of NH3 = 4.75) A 9.07 B 9.17 C 9.32 D 9.35 11 Instant ‘cold packs’ are often used by athletes to conveniently treat i njuries. One type of ‘cold pack’ is composed of powdered ammonium nitrate and water separated by a thin plastic membrane. When the pack is squeezed, the membrane breaks and ammonium nitrate dissolves in water spontaneously. Which line in the table gives the signs of H, S and G for the overall process? H S G A B C D

7 SRJC 9647/01/PRELIM/2014 Turn Over] 12 Use of the Data Booklet is relevant to this question. The half-cells for four metals: Mg, P, Q and R were in turn connected in pairs and the potential difference was recorded. Temperature = 25oC The results obtained are as shown in the table below. Positive electrode Negative electrode e.m.f /V P Mg +2.10 Q Mg +2.72 Mg R +0.33 Rank the four metals in the order of decreasing reducing power. A Q > P > Mg > R B P > Q > Mg > R C R > Mg > P > Q D R > Mg > Q > P metal metal salt bridge V electron flow 1 mol dm-3 of the metal ion 1 mol dm-3 of the metal ion

8 SRJC 9647/01/PRELIM/2014 Turn Over] 13 W, X, Y and Z are four elements in Period 3. W is a conductor of electricity