IJC H2 CHEM P1 Students Copy

INNOVA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION in preparation for General Certificate of Education Advanced Level Higher 2 CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY Paper 1 Multiple Choice Additional Materials: Data Booklet Multiple Choice Answer Sheet 9647/01 30 August 2016 1 hour READ THESE INSTRUCTIONS FIRST Write your name and class on all the work you hand in. Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. There are forty 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. This document consists of 17 printed pages and 1 blank page. Innova Junior College [Turn over

2  IJC 2016 Prelim/9647/01 [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 Carbon disulfide, CS2, is a volatile liquid used in the production of cellophane which is used for food packaging. On combustion, CS2 is oxidised as follows: CS2(g) + 3O2(g) CO2(g) + 2SO2(g) A 20 cm3 sample of carbon disulfide vapour is ignited with 100 cm3 of oxygen. The final volume of gas after burning is treated with an excess of aqueous alkali. Which percentage of this final volume dissolves in alkali? (All volumes are measured at room temperature and pressure.) A 20% B 40% C 60% D 80% 2 Consider the following half-equations C2O42– 2CO2 + 2e– Fe2+ Fe3+ + e– MnO4– + 8H+ + 5e– Mn2+ + 4H2O What volume of 0 .01 mol dm–3 potassium manganate(VII) is needed to completely oxidise 25.0 cm3 of an acidified solution of 0.01 mol dm–3 FeC2O4? A 5 cm3 B 7.5 cm3 C 10 cm3 D 15 cm3 3 Which electronic configuration represents an element that forms a simple ion with a charge of –3? A 1s22s22p63s23p1 B 1s22s22p63s23p3 C 1s22s22p63s23p63d14s2 D 1s22s22p63s23p63d34s2

3  IJC 2016 Prelim/9647/01 [Turn over 4 Carbon dioxide is a gas at room temperature while silicon dioxide is a solid because A carbon dioxide contains double covalent bonds while silicon dioxide contains single covalent bonds. B instantaneous dipole – induced dipole attractions are weaker than permanent dipole – permanent dipole attractions. C carbon-oxygen bonds are less polar than silicon-oxygen bonds. D van der Waals’ forces are much weaker than covalent bonds. 5 Under which conditions will the behaviour of a gas be most ideal? pressure temperature A high high B high low C low high D low low 6 The enthalpy changes involving some oxides of nitrogen are given below: N2(g) + O2(g) → 2NO(g) ∆H = +180 kJ mol–1 2NO2(g) + 1 2O2(g) → N2O5(g) ∆H = –55 kJ mol–1 N2(g) + 5 2O2(g) → N2O5(g) ∆H = +11 kJ mol–1 What is the enthalpy change, in kJ mol–1, of the following reaction? 2NO(g) + O2(g) → 2NO2(g) A –114 B +114 C –136 D +136 7 A typical protein forms hundreds of hydrogen bonds and thousands of van der Waals’ forces in folding from primary to tertiary structures. Which of the following thermodynamic state functions of the protein best represents the folding process? G / kJ mol–1 H / kJ mol–1 S / J K–1 mol–1 A    B +  + C  +  D + + 

4  IJC 2016 Prelim/9647/01 [Turn over 8 When 1 mole of carbon dioxide gas solidifies as dry ice, 25.2 kJ of heat energy is evolved. The sublimation temperature of carbon dioxide is 78.5 C. What is the entropy change when 132 g of carbon dioxide gas solidifies at this temperature? A +130 J K1 B 130 J K1 C +389 J K1 D 389 J K1 9 A student set up the hydrogen electrode shown in the diagram below. What would have to be changed to make this a standard hydrogen electrode? A the acid solution used B the temperature of the gas and of the acid solution C the pressure of the gas D the metal comprising the electrode

5  IJC 2016 Prelim/9647/01 [Turn over 10 Use of the Data Booklet is relevant to this question. Using inert electrodes, a current was passed through two beakers containing aqueous silver sulfate and aqueous copper(II) nitrate, connected in series under standard conditions. What is the ratio of the mass of silver to copper deposited after the current was passed for t minutes? 0 A 0.59 0 B 0.85 1 C 1.70 1 D 3.40 11 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 equilibrium pressure was p. N2(g) + 3H2(g) 2NH3(g) What was the partial pressure of ammonia in the equilibrium mixture? A p 3 B p 4 C p 6 D 2p 7 12 Solid calcium hypochlorite pellets, Ca(C lO)2(s), are added to swimming pools to form HClO(aq), which kills disease-causing bacteria and algae. Ca(ClO)2(s) Ca2+(aq) + 2ClO(aq) ClO(aq) + H2O(l) HClO(aq) + OH(aq) What is the effect on the solubility of calcium hypochlorite and bacterial growth when pH decreases? solubility of calcium hypochlorite effect on bacterial growth A decreases more favourable B decreases less favourable C increases more favourable D increases less favourable A 1.00 mol dm-3 Cu(NO3)2(aq) 0.50 mol dm-3 Ag2SO4(aq) At 25 oC, 1 atm

6  IJC 2016 Prelim/9647/01 [Turn over 13 The dissociation constant, Kw, for the ionisation of water, H2O H+ + OH, at different temperatures is given below. temperature / °C Kw 0 1.15 x 10-15 25 1.00 x 10-14 50 5.50 x 10-14 What can be deduced from this information? A Only at 25 °C are [H+] and [OH-] equal. B The equilibrium lies furthest to the right at 0°C. C The forward reaction is exothermic. D The pH of water decreases as temperature increases. 14 A sparingly soluble salt, Mg3(PO4)2 dissociates in aqueous solution as follows: Mg3(PO4)2 3 Mg2+ + 2 PO43- Given that the solubility product, Ksp of Mg3(PO4)2 is Q, what is the value of [Mg 2+] in a saturated solution? A (9𝑄 4 ) 1 5 B ( 𝑄 27) 1 3 C ( 𝑄 108) 1 5 D (9𝑄 64) 1 3

7  IJC 2016 Prelim/9647/01 [Turn over 15. The reaction of hydrogen peroxide with iodide ions in an acidic solution is first order with respect to hydrogen peroxide as well as iodide ions, and zero order with respect to hydrogen ions. H2O2(aq) + 2H+(aq) + 2I (aq)  2H2O(l) + I2(aq) Two experiments were carried out. Which pair of diagram s represents the variation of [H2O2] and [H+] with time? Experiment 1: In the presence of excess I  Experiment 2: In the presence of excess I  and H2O2 A B C D [H2O2] time 0 [H+] time 0 [H2O2] time 0 [H+] time 0 [H2O2] time 0 [H+] time 0 [H2O2] time 0 [H+] time 0

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