SAJC Prelim P1 QNS STUDENT

1 [Turn Over ST ANDREW’S JUNIOR COLLEGE JC2 Preliminary Examinations Chemistry Higher 2 9647/01 Paper 1 Multiple Choice 17th September 2015 1 hour 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. There are 40 questions on this paper. Answer all questions. For each question there are four possible answers A, B, C and D. Ch oose the one you consider correct and record your choice in soft pencil on the separate Answer Sheet. Each correct answer will score one mar k. A mark will not be deducted for a wrong answer. Any rough working should be done in this booklet. This document consists of 25 printed pages including this page.

2 [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 mass percentage of magnesium in a mixture of magnesium chloride (Mr = 95.3) and magnesium nitrate (Mr = 148.3) was found to be 21.25%. What mass of magnesium chloride is present in 323 g of the mixture? A 151 g B 165 g C 172 g D 181 g 2 Which conversion results in a loss of electrons for the underlined species? A NO3 − to NO2 B NO2 − to NO3 − C S2O8 2− to SO4 2− D S4O6 2− to S2O3 2− 3 Which of the following pairs shows Gas Y deviating more from ideal gas behaviour than Gas X at the same temperature and pressure? Gas X Gas Y A HF HCl B H2O H2 C I2 Br2 D O2 NO2

3 [Turn Over 4 Use of the Data Booklet is relevant to this question. Which of the following shows the correct increasing trend for the angle of deflection when placed in an electric field? A Cl − < Ru3+ < Zn2+ B Ru3+ < Cl − < Zn2+ C Cl − < Zn2+ < Ru3+ D Zn2+ < Ru3+ < Cl − 5 Which of the following cannot form dimers? A CH3COOH B CH3CHO C AlCl3 D NO2 6 Which of the following species is planar and does not have dative bonding? A PO4 3− B SO4 2− C CO3 2− D NO3 −

4 [Turn Over 7 The behavior of Group II sulfates and hydroxides show different trends down the group. Group II sulfates become less soluble down the group, while Group II hydroxides become more soluble down the group. Which of the following statements helps to explain this trend? A Down the group, the magnitude of the lattice energy of Group II hydroxides has a more significant decrease than the magnitude of the sum of hydration energies of the ions. B Down the group, the magnitude of the lattice energy of Group II sulfates has a more significant decrease than the magnitude of the sum of hydration energies of the ions. C The hydration energy of the sulfate anion is larger in magnitude than the hydroxid e anion. D The magnitude of the lattice energy of Group II ionic compounds increases down the group. 8 Phosphorus exists in several allotropes. White phosphorus has the structure P 4, while black phosphorus has a structure similar to graphite. While the transformation of white phosphorus to black phosphorus is spontaneous, the rate is very slow, and usually involves the use of a metal salt catalyst to increase its rate. Which of the following is true? A Black phosphorus has a simple molecular structure. B H for the transformation of white phosphorus to black phosphorus is less than zero. C S for the transformation of white phosphorus to black phosphorus is greater than zero. D The uncatalysed reaction of transforming white phosphorus to black phosphorus has a small activation energy.

5 [Turn Over 9 What is the half-life of a first-order reaction where the concentration of the reactant drops to 1 5 of its initial concentration after 51 minutes? A 20 min B 22 min C 24 min D 26 min 10 The graph below shows the change in rate for an enzyme-catalysed reaction. Which of the following statements is incorrect? A At low [substrate], the rate is first order with respect to [substrate]. B At low [substrate], the reaction slows down due to increasing concentration of the products. C At high [substrate], the rate is constant as all the enzyme active sites are used up. D At high [substrate], increasing [enzyme] increases the rate.

6 [Turn Over 11 A ketone such as propanone can undergo a rearrangement of its atoms to form an enol when dissolved in a non-polar solvent. Enols exist together with their ketone forms in equilibrium. ∆H = +48 kJ mol-1 Which of the following statements can be determined from the information above? A Increasing the temperature results in the shift of the position of equilibrium to the left. B The entropy change of the reaction is positive under aqueous conditions. C Adding of warm alkaline iodine results in the shift of the position of equilibrium to the right. D Adding sodium metal results in the shift of the position of equilibrium to the right. 12 Which of the following mixtures will result in a significant pH change when a small amount of acid is added? A 20 cm3 of 1 mol dm-3 H2CO3 and 20 cm3 of 1 mol dm-3 KHCO3 B 20 cm3 of 1 mol dm-3 HCl and 20 cm3 of 1 mol dm-3 CH3CH2NH2 C 10 cm3 of 1 mol dm-3 NaOH and 20 cm3 of 1 mol dm-3 NH4Cl D 10 cm3 of 1 mol dm-3 HCl and 20 cm3 of 1 mol dm-3 Mg(CH3CH2COO)2

7 [Turn Over 13 The table below shows the numerical values of the solubility products for some salts. Salt Pb(OH)2 Zn(OH)2 ZnCO3 Ag2CO3 Ksp 1.4 x 10-20 3.0 x 10-17 1.4 x 10-11 8.1 x 10-12 Which statement is correct? A Pb(OH)2 is more soluble than Zn(OH)2. B Zn(OH)2 is more soluble than ZnCO3. C Ag2CO3 is more soluble than ZnCO3. D Pb(OH)2 is more soluble than Ag2CO3. 14 Use of the Data Booklet is relevant to this question. Pure copper wires when used in electrochemical cells are partially submerged in the electrolyte. Which aqueous electrolyte can be used such that the copper wires do not dissolve? A KNO3 B K2S2O8 C Na2Cr2O7 D Na2S4O6

8 [Turn Over 15 3.96 g of metal was deposited when 1.602 x 104 C of electricity was passed through a molten electrolyte. Which of the following could be the electrolyte? A TiCl B TiSO4 C Ti2O3 D TiO2 16 The graph below shows the variation in the boiling points for eight consecutive elements in the Periodic Table, all with atomic number between 10 and 20. Which of the following statements is true? A Element H forms an acidic oxide. B Element K does not conduct electricity. C Element E and beryllium are in the same group. D The element preceding E has a smaller atomic radius than E. Atomic no. A B C D E F G H Boiling point F E H G I L K J

9 [Turn Over 17 Radium is a radioactive element below barium in the Periodic Table. Which statement concerning radium is not true? A It is a good conductor of electricity. B Radium nitrate has a higher thermal stability than barium nitrate. C Radium dissolves in water at room temperature to form a strongly basic solution. D Radium has an outermost electronic configuration of 6s2. 18 Chlorine and iodine are both elements in Group VII, but have some differences i n their reactivity and properties of their compounds. Which of the following would increase from chlorine to iodine? A oxidation state of sulfur when the halogens reacts with sodium thiosulfate B bond energy of molecules of the elements C strength of the van der Waals’ forces between molecules of the elements D solubility product of the silver halide 19 Which of the following statements is true about the d -block elements in Period 4 and their compounds? A Chromium has the most number of oxidation states. B Cu+ has 1 unpaired electron in its ground electr