SAJC Prelim P1

ST. ANDREW’S JUNIOR COLLEGE Higher 1 PRELIMINARY EXAMINATION 2009 CHEMISTRY PAPER 1 8872/ 01 17 September 2009 50 minutes Candidates answer all the questions on the Optical Answer Sheet Additional Materials: Optical 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 and civics group on the Answer Sheet. There are thirty questions in these sections. 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. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. This paper consists of 12 printed pages and 1 blank page.

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3 Section A (25 marks) For each qu estion there are four possible answers, A, B, C and D. Choose the one you consider to be correct. 1 Which of the following statements is not true? A One mole of water contains 2 moles of hydrogen atoms. B One mole of chlorine gas contains 6.02 × 1023 atoms of chlorine. C One mole of ammonia has a mass of 17.0 g. D One mole of sodium chloride contains 1.204 × 1024 ions. 2 In an experiment, 0.0013 mole of a metallic salt, reacted completely with 20.80 cm3 of 0.025 mol dm-3 MnO4 -. The half equation for the reduction of MnO4 - is shown below: MnO4 - + 8H+ + 5e → Mn2+ + 4H2O Given the final oxidation number of the metal in the salt was +5, what would the original oxidation number of the metal be? A +1 B +2 C +3 D +4 3 In which of the compound does sulfur show the lowest oxidation state? A H2S B SCl2 C SO3 2- D S2O3 2- [Turn Over

4 4 The use of t he Data Booklet is relevant to this question. Which of the following species has more electrons than protons and more protons than neutrons? [D = ] H2 1 A D- B OH- C OD- D He+ 5 The orbitals of a carbon atom may be represented as shown. 1s 2s 2p Which diagram represents the arrangement of electrons in the ground state of the atom? A B C D

5 6 The diagra m shows a liquid flowing from a burette and a charged rod is brought close to the flow. Which could not be a possible identity of the liquid? A CHCl3 B C2H6 C C2H5OH D C2H5Br 7 How many σ and π bonds are there in the molecule, CH3CH=CH2? σ π A 4 0 B 4 1 C 7 1 D 8 1 8 Which of the following compounds consists of atoms or molecules held together only by van der Waals’ forces? A Sodium B Silicon C Iodine D Water [Turn Over

6 9 The radius a nd charge of each of the five ions are shown in the table below. Ion M+ Q+ R 2+ T— W 2- radius / nm 0.13 0.19 0.16 0.13 0.16 The ionic solids MT, QT and RW are of the same lattice type. What is the correct order of their lattice energies placing the one with the highest numerical value first? A MT > QT > RW B MT > RW > QT C RW > MT > QT D RW > QT > MT 10 Which of the following has a positive ∆H value? A Na(s) → Na(g) B CH4(g) + 2O2(g) → CO2(g) + 2H2O(l) C NaOH(aq) + CH3COOH(aq) → CH3COO-Na+(aq) + H2O(l) D 2O(g) → O2(g) 11 When 1.00 g of 1,2-ethanediol was burned under a container of water, it was found that 100 g of water was heated from 25°C to 70°C. If the specific heat capacity of water is 4.2 J K-1 cm-3, what is the enthalpy change of combustion of 1,2-ethanediol in kJ mol-1? A -18.90 B -133.60 C -1172 D -8281

7 12 The enthalp y change of neutralisation between 1 mole of HCl and 1 mole of NaOH is given below. NaOH(aq) + HCl (aq) → NaCl(aq) + H2O(l) ∆H = -57.3 kJ mol-1 The enthalpy change of neutralisation between 1 mole of CH3COOH and 1 mole of NaOH is less than -57 kJ mol-1. NaOH(aq) + CH3COOH (aq) → CH3COO-Na+(aq) + H2O(l) ∆H < -57.3 kJ mol- 1 fference between these two values? D CH3COOH can form hydrogen bonds with water but not HCl. 13 aq) + H2O2(aq) + 2H+(aq) → I2(aq) + 2H2O(l) mation? ons of H2O2 and I-. to H2O2. D H+ acts as a catalyst in the reaction. 14 about the forward and reverse reactions of a system A onstant for the forward reaction equals the rate constant for the reverse D he forward reaction to that of the reverse reaction Which state ment best explains the di A Heat is lost to the surroundings. B Less than 1 mole of H2O is formed. C Dissociation of CH3COOH is endothermic. The rate equation for th e reaction 2I-( is: rate = k [H2O2] [I-], where k is the rate constant. Which of the following conclusions cannot be drawn from the above infor A The value of k is independent of the concentrati B The reaction is first order with respect C The reaction is second order overall. Which of the following statements at dynamic equilibrium is correct? The rate c reaction. B Both the forward and reverse reactions have stopped. C The rates of both forward and reverse reactions are equal to zero. The ratio of the rate constant for t

8 equals the e quilibrium constant. [Turn Over 15 An equilibrium is represented by the following equation: C (s) + H2O (g) H2 (g) + CO (g); H > 0 Which of the following changes would result in an increase in yield of H2 (g)? m C adding more solid carbon D increasing the pressure of the system 6 pH of the resulting mixture after 10.00 cm3 of 0.025 mol dm-3 of c acid is added to 15.00 cm3 of 0.015 mol dm-3 of sodium hydroxide? C 11.00 D 12.00 7 when water is added C acid dissociation constant, Ka, increases as more water is added D acid dissociation constant, Ka, decreases as more water is added 8 , would result in a buffer NaOH C 0.10 mol dm-3 CH3COOH and 0.05 mol dm-3 NaCl D 0.05 mol dm-3 HCl and 0.05 mol dm-3 NaOH A adding a cat alyst B increasing the temperature of the syste 1 What is the hydrochlori A 2.00 B 3.00 1 Which of the following statements represents the correct changes to a sample of aqueous propanoic acid? A degree of dissociation, α, increases as more water is added B degree of dissociation, α, decreases as more water is added 1 Which of the following mixtures, mixed at equal volumes solution? A 0.05 mol dm-3 CH3COONa and 0.10 mol dm-3 HCl B 0.10 mol dm-3 CH3COOH and 0.05 mol dm-3

9 19 g was measured. asing pH value of the resulting solutions formed by these d C Na2O, Al2O3, P4O10 D P4O10, Al2O3, Na2O 0 der certain conditions. Which t it can form Al2Cl6? ns. C AlCl3 has a lower energy content than Al2Cl6. D Weak van der Waals’ forces exist between AlCl3 molecules. 21 uscalure is a sex hormone found in fruit flies and has the structure below. 2)12CH3 is correct? mate (VI) green on warming. C etric isomers. D It reacts with hot acidified potassium manganate (V II) to give CH 3(CH2)7CHO as one of the products [Turn Over Na2O, Al2O3 and P4O10 are dissolved separately in water and the pH of the resultin solutions What is the order of incre oxi es? A A l2O3, P4O10, Na2O B Al2O3, Na2O, P4O10 2 Aluminium chloride, AlCl3 can form a dimer, Al2Cl6, un sta ement best explains why A Al can expand its octet of eight valence electro B Al has an empty orbital. M CH3(CH2)7CH=CH(CH Which of the following about muscalure A It can turn orange potassium dichro B It reacts wit h 2 moles of hydrogen. It has a pair of geom

10 2 w t one product a gas at room temperature and droxide C oxidation of methanal with acidified potassium manganate(VII) D substitution of propanol by hydrogen bromide 23 student wants to produce propanone and ethanoic acid from 2-chloro-3-methylbutane. -chloro-3-m propanone and ethanoic acid 2 In hich of these processes is at leas pressure? A d