ACJC H1 CHEM P1 Qns ans

ANGLO-CHINESE JUNIOR COLLEGE DEPARTMENT OF CHEMISTRY Preliminary Examination CHEMISTRY 8872/01 Higher 1 Paper 1 Multiple Choice 29 August 2016 50 minutes Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluids. Write your name, index number and tutorial class 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 your 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. The use of an approved scientific calculator is expected, where appropriate. This document consists of 14 printed pages. 8872/01/ Prelim/16 ANGLO-CHINESE JUNIOR COLLEGE © ACJC 2016 Department of Chemistry [Turn over

2 © ACJC 2016 8872/01/Prelim/2016 [Turn over 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 Which statement about one mole of a metal is always true? A It contains the same number of atoms as one mole of hydrogen atoms. B It contains the same number of particles as 1 12 mole of 12C. C It has the same mass as one mole of hydrogen atoms. D It is liberated by one mole of electrons. 2 The discharge of the nickel-cadmium rechargeable battery is based upon the following overall reaction. Cd + 2NiOOH + 4H2O Cd(OH)2 + 2Ni(OH)2.H2O What is the oxidation number of nickel at the beginning and at the end of the reaction? beginning end A +1.5 +2 B +2 +3 C +3 +2 D +3 +4 3 Elements J and Q have the following successive ionisation energies in kJ mol –1 1st 2nd 3rd 4th 5th 6th 7th J 587 1817 2745 11577 14842 18379 23326 Q 870 1790 2698 3610 5668 6820 13200 What is the likely formula of the compound that is formed when J reacts with Q? A JQ3 B J2Q3 C J3Q2 D J2Q

3 © ACJC 2016 8872/01/Prelim/2016 [Turn over 4 The unsaturated diketone as shown below is excreted by the bombardier beetle. What are the numbers of sp, sp 2 and sp 3 hybridised carbon atoms in the product formed when this diketone is reacted with HCN in the presence of a trace amount of KCN? sp sp2 sp3 A 0 6 3 B 1 5 3 C 2 4 3 D 3 2 4 5 Which of the following statements about the properties associated with ionic and covalent bonds is correct? A Some covalent compounds can serve as an electrolyte in water. B Ionic bonds and covalent bonds cannot occur in the same compound. C Ionic compounds and metals can conduct electricity in both the solid and liquid states. D Any covalent compounds that have both hydrogen and oxygen atoms in its molecule can definitely form intermolecular hydrogen bond with itself. 6 In which of the following pairs does the first species have a larger bond angle than the second? A CH4, CH3+ B NCl3, BH3 C XeF4, SF6 D H2O, H2S

4 © ACJC 2016 8872/01/Prelim/2016 [Turn over 7 Which is the most likely structure of a molecule of dinitrogen pentoxide, N 2O5 showing its bond angles? A B C D 8 Which of the following solids consists of particles held together only by van der Waals’ forces? A NaCl B H2O C Cu D Ar

5 © ACJC 2016 8872/01/Prelim/2016 [Turn over 9 In which one of the following pairs does the first molecule have a larger dipole than the second? A and B and C HCl and HF D SO3 and SO2 10 The radioactive decay of element M is a first-order process. It takes 32 seconds for 4 g of element M to decay 2 g. How long will it take 0.25 g of M to decay to 0.0625 g? A 32 seconds C 128 seconds B 64 seconds D 160 seconds 11 This question concerns the magnitude of lattice energies of the following four ionic compounds. CaBr2 LiCl MgCl2 NaBr Which sequence gives the lattice energies in order of increasing magnitude? A CaBr2 LiCl MgCl2 NaBr B LiCl NaBr MgCl2 CaBr2 C MgCl2 CaBr2 NaBr LiCl D NaBr LiCl CaBr2 MgCl2 CH3 CO CH3 Cl CO Cl CH3 CC Cl Cl CH3 Cl CC CH3 Cl CH3

6 © ACJC 2016 8872/01/Prelim/2016 [Turn over 12 H3PO4 is a triprotic acid which has three acid dissociation constants. The table below shows the first, second and third acid dissociation constants, Ka, respectively. dissociation equilibrium in aqueous solution Ka/mol dm–3 first H3PO4(aq) + H2O(l) H3O+(aq) + H2PO4–(aq) 7.5 x 10–3 second H2PO4–(aq) + H2O(l) H3O+(aq) + HPO42–(aq) 6.2 x 10–8 third HPO42–(aq) + H2O(l) H3O+(aq) + PO43–(aq) 2.2 x 10–13 Which of the following ranks the conjugate bases in order of increasing basicity? lowest highest A PO43– HPO42– H2PO4– B H2PO4– HPO42– PO43– C HPO42– PO43– H2PO4– D HPO42– H2PO4– PO43– 13 Which of the following compounds is not a product of the reaction between an oxide of a Period 3 element and water? A NaOH C Al(OH)3 B H3PO4 D H2SO3 14 Which of the following statements concerning the third period elements (sodium to sulfur) and their compounds is incorrect? A The elements become more electronegative from sodium to chlorine. B Aluminium oxide is the only oxide which is amphoteric. C pH of the chlorides increases. D Phosphorus is the only element that burns in air to form a solid white oxide, which reacts vigorously with water to form an acidic solution.

7 © ACJC 2016 8872/01/Prelim/2016 [Turn over 15 Across a period, the elements show an increase in their maximum oxidation number in their oxides. Which of the following explains this? A an increase in the number of electrons in the outer shell B an increase in the electronegativity of the element C an increase in the ease of losing an electron D an increase in the size of an atom 16 The following graph shows the first ionisation energies of eight consecutive elements J to R, which have atomic numbers between 3 to 20 in the Periodic Table. Which of the following statements about the elements is false? A Oxides of Q react with dilute H2SO4(aq). B Chlorides of M are good conductor of electricity. C The ionic radius of J is larger than the ionic radius of K. D N forms a chloride which reacts with water to give a neutral solution. 17 Which one of the following organic compounds does not exist? A An ester which is a structural isomer of a carboxylic acid, C