NYJC H1 Chemistry P1

NANYANG JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 1 CHEMISTRY 8872/01 Paper 1 Multiple Choice 26 September 2014 50 minutes 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 tutor’s name 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 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. This document consists of 15 printed pages and 0 blank page. [Turn over

2 H1 Chemistry 8872/02 NYJC J2/14 PX Section A For each question there are four possible answ ers, A, B, C and D. Choose the one you consider to be correct. 1 0.02 mol of C xHyNO2 was burned in excess oxygen as shown by the equation below. CxHyNO2 + aO2  xCO2 + NO2 + 2 y H2O The gases that were produced were first passed th rough a U -tube containing phosphorus pentoxide and then bubbled through 0.25 mol of NaOH(aq). The equations illustrating the reactions of the gases with NaOH(aq) are as shown below. CO2 + 2NaOH  Na2CO3 + H2O 2NO2 + 2NaOH  NaNO2 + NaNO3 + H2O The phosphorus pentoxide U -tube increased in mass by 1.15 g and the excess NaOH(aq) required 40.00 cm3 of 0.875 mol dm3 H2SO4 for complete reaction. What is the ratio of x:y? A 2:3 B 4:3 C 4:7 D 8:7 2 An acidified solution of the salt KClO z will oxidise Ti 3+(aq) to Ti 4+(aq) quantitatively, the chlorine being reduced to Cl(aq). When 0.170 g of the salt KClO z was reacted with 0.400 mol dm 3 Ti3+(aq) in the presence of H+(aq), 24.50 cm3 of Ti3+(aq) was needed for complete reaction. What is the value of z? A 1 B 2 C 3 D 4

3 H1 Chemistry 8872/01 NYJC J2/14 PX [Turn over 3 Which of the following ions has one more electron in the third quantum shell than in the second quantum shell? A Ca2+ B Cl C Sc+ D S2 4 In w hich of the following pairs does species I have a smaller bond angle than species II? I II A AsCl3 ClO2  B CS2 SO4 2- C NO2  NO3  D PH4 + SF6 5 Which of the following statements about the properties associated with ionic and covalent bonds is correct? A The only covalent compounds with high melting points are those in which hydrogen bonds occur. B Any covalent compound that contains both oxygen and hydrogen in its molecule forms hydrogen bonds. C Any ioni c bonds and covalent bonds cannot both occur in the same compound. D Ionic compounds differ from metals in that ionic com pounds do not conduct electricity in the solid state.

4 H1 Chemistry 8872/02 NYJC J2/14 PX 6 The enthalpy change of combustion of butanone, C2H5COCH3, is 2440 kJ mol1. The approximate enthalpy changes of formation are given in the table. Substance Hf o / kJ mol1 CO2(g) 394 H2O(l) 286 What is the enthalpy change of formation of butanone? A 1760 B 280 C +280 D +1760 7 Use of the Data Booklet is relevant to this question. Octane can react with bromine to form bromooctane and hydrogen bromide. 2C8H18 + 2Br2  2C8H17Br + 2HBr What is the enthalpy change of the reaction? A 86 kJ mol1 B 43 kJ mol1 C +58 kJ mol1 D +116 kJ mol1

5 H1 Chemistry 8872/01 NYJC J2/14 PX [Turn over 8 A radioactive element has two isotopes, G and H, with half -lives of 5 min and 15 min respectively. An experiment starts with 4 times as many atoms of G as of H. Radioactive decay is a first-order reaction. How long will it be before the number of atoms of G left equals the number of atoms of H left? A 5 min B 10 min C 15 min D 20 min 9 In the diagram, curve X was obtained by observing the decomposition of 100 cm3 of 1.0 mol dm3 hydrogen peroxide, catalysed by manganese(IV) oxide. Which alteration to the original experimental conditions would produce curve Y? A adding water B adding some 0.1 mol dm3 hydrogen peroxide C using less manganese(IV) oxide D lowering the temperature volume of oxygen formed time 0 X Y

6 H1 Chemistry 8872/02 NYJC J2/14 PX 10 For the reaction N2O4(g) Ý 2NO2(g) the numerical value of Kc is 0.273 at 500 K and is 0.339 at 600 K. What deduction can be made from this information? A The yield of NO2 will increase at higher pressure. B The yield of NO2 is independent of temperature. C The forward reaction is endothermic. D The value of Kc depends on the amount of N2O4 initially present. 11 PCl5 decomposes on heating according to the following equation. PCl5(g) ⇌ PCl3(g) + Cl2(g) When 0.8 mol of PCl5 were put into a 2 dm 3 container and heated, the equilibrium mixture contained 0.48 mol of chlorine. What is the numerical value of the equilibrium constant, Kc, at the temperature of the experiment? A 0.144 B 0.288 C 0.360 D 0.720 12 Which statement is correct about the following reaction? C6H5O + HCl  C6H5OH + Cl A C6H5OH is a proton acceptor. B C6H5O is a Bronsted base. C Cl is a Bronsted acid. D HCl is the conjugate base of Cl.

7 H1 Chemistry 8872/01 NYJC J2/14 PX [Turn over 13 A 0.100 mol dm3 aqueous solution of an acid HX has a pH of 4.0. Which statement is correct? A Adding an equal volume of water to the acid solution increases the pH to 8.0. B HX is a weak acid. C The hydrogen ion concentration is 0.100 mol dm3. D 1 dm3 of the acid solution requires 1.00  104 mol NaOH for neutralisation. 14 Which statement concerning only the elements in the third period, sodium to argon, is correct? A The element that has exactly four atoms in its molecule is sulfur. B The element with the highest electrical conductivity is aluminium. C The element with the highest melting point is aluminium. D The element with the largest anion is chlorine. 15 Which compound is not a product of the reaction between an oxide of a third period element and water? A NaOH B H2SiO3 C H3PO4 D H2SO4 16 Four carbon-carbon bonds are labelled in the diagram. CH CH C O CH3 w x y z Which bonds are made up of a sp2sp2 overlap? A w and y only B w, x and y only C w, x, y and z D x, y and z only

8 H1 Chemistry 8872/02 NYJC J2/14 PX 17 Testosterone is an important h ormone in the development of the male reproductive tissues. O OH testosterone Which statement about this compound is not correct? A It decolourises aqueous bromine. B It decolourises cold, dilute MnO4  ions. C It can exhibit geometric isomerism to give two isomers. D It can undergo reduction with sodium borohydride to give a product with the molecular formula, C19H30O2. 18 Which of the following product s could be formed by the action of hot alkaline potassium manganate(VII) on an alkene of formula C4H8? A CO2, (CH3)2CO, CH3CH2COOH B HCOO, CH3CO2  CH3CH2CO2  C CO3 2, (CH3)2CO, CH3CO2  D HCOO, (CH3)2CO, CH3CH2CO2 

9 H1 Chemistry 8872/01 NYJC J2/14 PX [Turn over 19 Compound Z is heated under reflux with alkaline potassium dichromate(VI). OH OH Compound Z What is the main product? A COOH COOH COOH COOH B COO  COO  COO  COO  C OH OH COO  D COO O

10 H1 Chemistry 8872/02 NYJC J2/14 PX 20 2-bromopropane may be used as the starting material to manufacture (CH3)2CHCO2H. Which sequence would be the most suitable? A (CH3)2CHBr  (CH3)2CHOH  (CH3)2CHCO2H B (CH3)2CHBr  (CH3)2CHCN  (CH3)2CHCO2H C (CH3)2CHBr  (CH3)2CHOH  (CH3)2CHCN  (CH3)2CHCO2H D (CH3)2CHBr  (CH3)2CHCN  (CH3)2CHCH2OH  (CH3)2CHCO2H 21 The first stage in the synthesis of Antipyrine, a d