2012 RVHS H1 Chemistry Paper 1

1 River Valley High School 8872/01/PRELIM/12 [Turn over Prelim Examination 2012 Year 6 H1 Chemistry 8872 Paper 1 RIVER VALLEY HIGH SCHOOL YEAR 6 PRELIMINARY EXAMINATION CANDIDATE NAME CLASS 6 CENTRE NUMBER S INDEX NUMBER H1 CHEMISTRY 8872/01 Paper 1 Multiple Choice 21st September 2012 50 minutes Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, class, c entre number and index number on the Answer Sheet in the spaces provided. 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. ________________________________________________________________________ This document consists of 12 printed pages.

2 River Valley High School 8872/01/PRELIM/12 [Turn over Prelim Examination 2012 Year 6 H1 Chemistry 8872 Paper 1 Section A For each question there are four possible answers, A, B, C and D. Choose the one you consider to be correct. 1 Methane was burned with a faulty Bunsen burner. As a result, a mixture of carbon dioxide and carbon monoxide was produced in a ratio of 98:2, together with water vapour. What was the volume of oxygen gas used when y dm3 of methane was burned? A dm3 B dm3 C dm3 D dm3 2 An ion of metal M can be oxidised by potassium manganate( VII) in acid solution to form MO3−. In an experiment, 1.25  10−3 mol of the ion of M required 37.5 cm 3 of 0.0200 mol dm−3 potassium manganate(VII) for complete reaction. What is the initial oxidation state of the ion of M? A +1 B +2 C +3 D +4 3 The table gives the successive ionization energies for element X. 1st 2nd 3rd 4th 5th 6th Ionization energies/kJ mol−1 950 1800 2700 4800 6000 12300 What could be the formula of the bromide of X? A XBr B XBr2 C XBr3 D XBr4

3 River Valley High School 8872/01/PRELIM/12 [Turn over Prelim Examination 2012 Year 6 H1 Chemistry 8872 Paper 1 4 Which of the following electrostatic attraction is not present in a sample of CH3F? A permanent dipole-permanent dipole interactions B instantaneous dipole-induced dipole interactions C hydrogen bonds D covalent bonds 5 Trimethoprim (TMP) is used for the treatment of urinary tract infections. It has the following structure: Trimethyoprim (TMP) N N C H H NH2 N HH OCH3 CH3O C H H H O Z yx w In which sequence is the bond angles quoted in decreasing order? A y > w > z > x B x > y > z > w C y > z > w > x D x > y > w > z 6 Which of the following molecules do not have all the atoms lying on the same plane? A H2O B PH3 C AlCl3 D ICl3

4 River Valley High School 8872/01/PRELIM/12 [Turn over Prelim Examination 2012 Year 6 H1 Chemistry 8872 Paper 1 7 A chemist discovered that an element X forms X2+ ions with the electronic configuration 1s2 2s2 2p6 3s2 3p6 3d8. Element X has a relative atomic mass of 2y+5, with y representing the proton number. How many neutrons are present in an atom X. A 28 B 30 C 32 D 33 8 Which of the following oxides is unlikely to dissolve in aqueous sodium hydroxide? A MgO B Al2O3 C SiO2 D SO2 9 Nitrogen dioxide decomposes on heating according to the following equation. 2NO2(g) = 2NO(g) + O2(g) When 2 mol of ni trogen dioxide is placed in a 4 dm3 container and heated, the equilibrium mixture contained 0.8 mol of oxygen. What is the numerical value of the equilibrium constant, Kc, at the temperature of the experiment? A 0.0889 B 0.800 C 3.20 D 12.8 10 Which statement about the effect of a catalyst on a reversible reaction is correct? A It increases the yield of product in an equilibrium. B It increases the equilibrium constant for the forward reaction. C It increases the rate of the forward reaction and decreases the rate of the reverse reaction. D It increases the rate constant for both the forward and the reverse reaction.

5 River Valley High School 8872/01/PRELIM/12 [Turn over Prelim Examination 2012 Year 6 H1 Chemistry 8872 Paper 1 11 Given the following data and energy cycle: N2O4(g) → 2NO2(g) ∆H = +57.9 kJ mol–1 NO(g) + 2 1 O2(g) → NO2(g) ∆H = −56.6 kJ mol–1 Determine the enthalpy change of the following reaction: 2NO(g) + O2(g) → N2O4(g) A +114.5 kJ mol–1 B −114.5 kJ mol–1 C +171 kJ mol–1 D −171 kJ mol–1 12 A 1 mol sample of a monobasic weak acid, CH 3COOH, is diluted at constant temperature to a volume V. CH3COOH(aq) + H2O(l) = CH3COO–(aq) + H3O+(aq) Which of the following graphs correctly illustrates the relationship between V and the acid dissociation constant, Ka, of CH3COOH? A C B D Ka 0 V Ka 0 V Ka 0 V Ka 0 V

6 River Valley High School 8872/01/PRELIM/12 [Turn over Prelim Examination 2012 Year 6 H1 Chemistry 8872 Paper 1 13 Which one of the following elements has the same oxidation state in all of its known compounds? A beryllium B bromine C nitrogen D sulfur 14 Lattice energy of an ionic salt XY is less exothermic than MgO. Which of the following about the ionic radii of X and Y and the charges of X and Y is correct when compared with that of magnesium and oxygen? Ionic radius Charge of ions X Y X Y A Same Same Higher Same B Smaller Smaller Same Same C Larger Larger Higher Higher D Larger Larger Lower Lower 15 The product of the concentrations of X and Y, [X][Y], is plotted against time, t, for the following second-order reaction. X + Y → Z Which graph would be obtained? A B C D [X][Y] t [X][Y] t [X][Y] t [X][Y] t 0 0 0 0

7 River Valley High School 8872/01/PRELIM/12 [Turn over Prelim Examination 2012 Year 6 H1 Chemistry 8872 Paper 1 16 Which of the following can be used to explain this difference in Kw values? Temperature / K Kw / mol2 dm-6 289 5 x 10-15 298 1 x10-14 A H+(aq) and OH−(aq) are formed through endothermic reaction. B Formation of H+(aq) and OH−(aq) is favoured at lower temperatures. C The pH of water is independent of the temperature. D The concentration of water is lower at higher temperature. 17 Element X is a solid with a very low electrical conductivity at room temperature. It forms only one chloride, which is a liquid at room temperature and is a non-conductor of electricity. The chloride hydrolyses in water forming a white solid and a strongly acidic solution. Which of the following could be X? A Aluminium B Phosphorus C Silicon D Sulfur 18 The bond dissociation energy of H−C l is 431 kJ mol −1. In which of the following processes is 431 kJ of energy released? A HCl(g) → H(g) + Cl(g) B H(g) + Cl(g) → HCl(g) C HCl(g) → ½H2(g) + ½Cl2(g) D ½H2(g) + ½Cl2(g) → HCl(g)

8 River Valley High School 8872/01/PRELIM/12 [Turn over Prelim Examination 2012 Year 6 H1 Chemistry 8872 Paper 1 19 Deuterium, D, is a heavy isotope of hydrogen. Deuteriobenzene is reacted with a mixture of chlorine gas under suitable conditions such that only monosubstitution takes place. Assuming that the carbon–deuterium bond is broken as easily as a carbon–hydrogen bond, which proportion of the chlorinated products will be 3–chlorodeuteriobenzene? D D Cl Deuteriobenzene 3-chlorodeuteriobenzene A 16% B 20% C 33% D 45% 20 Which of the following could be best used to distinguish between hex -1-ene and methylbenzene? A acidified K2Cr2O7 B Br2 in CCl4 C I2 in NaOH(aq) D concentrated sulfuric acid 21 Which hy