H1 Paper 1 (Student Copy)

ANGLO-CHINESE JUNIOR COLLEGE DEPARTMENT OF CHEMISTRY Preliminary Examination CHEMISTRY 8872/01 Higher 1 Paper 1 Multiple Choice 12 September 2012 50 minutes Additional Materials: Multiple Choice Answer Sh eet Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, 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 care fully. Each correct answer will score one mark. A mark wi ll not be deducted for a wrong answer. Any rough working should be done in this booklet. This document consists of 11 printed pages. 8872/Prelims/12 ANGLO-CHINESE JUNIOR COLLEGE © ACJC 2012 Department of Chemistry [Turn over

© ACJC 2007 9746/01/Prelim/07 2 Section A For each question there are four possible answers, A, B, C and D. Choose the one you consider to be correct. 1 Which of the following contains 1.60 × 10 22 of atoms? A 7.98 g of ethane B 1.86 g of chlorine free radicals (•C l) C 638 cm 3 of neon at 298 K and 1 atm D 5.95 dm 3 of hydrogen gas at 273 K and 1 atm 2 In an experiment, 20 cm 3 of a gaseous hydrocarbon C xHy, was completely burnt in 150 cm 3 of excess oxygen. The gaseous volume after the reaction was 120 cm 3 and treatment with aqueous potassium hydroxide dec reased the volume to 80 cm 3. All volumes were measured under room temperature and pressure. What is the molecular formula of the hydrocarbon? A C2H4 C C 4H8 B C2H6 D C 4H10 3 Iron poisoning in children is usually caused by exc essive intake of iron supplement pills. The amount of iron which will ca use poisoning depends on the size of the child. It was found that as little as 590 mg of Fe 2+ can be fatal to a 12 kg child. How many 325 mg FeSO 4 pills would it take to cause a fatal effect on a 1 2 kg child? A 3 C 5 B 4 D 6 4 In which of the following compounds does vananium h ave the lowest oxidation state? A VO 3 - C VO 2 + B VO 2+ D V 2O5

© ACJC 2007 9746/01/Prelim/07 [Turn over 3 5 In an experiment, 16.0 cm 3 of 0.3 mol dm -3 of acidified dichromate( VI ) ions was used to oxidise 28.8 cm 3 of 0.5 mol dm -3 of Gn+ . What is the change in oxidation number for element G? A -3 C +2 B -1 D +4 6 In 1996, Professor Hoffman and a group of scientist s discovered a new element known as Ununbium, Uub. An atom of Uub can be forme d by fusion of a lead nucleus with the nucleus of an isotope of element H as follows: 208 82 Pb + H → 277 112 Uub + 1 neutron What is element H? A Cu C Ge B Ga D Zn 7 Why is the first ionisation energy of oxygen lower than that of nitrogen? A Oxygen is more electronegative than nitrogen. B Oxygen forms anions more readily. C The electron to be lost is paired with another electron. D The oxygen atom is larger than the nitrogen atom. 8 In which of the following sets does the first compo und have a larger bond angle than the second compound? A H 2S and H 2O C PC l3 and NC l3 B ClO3 - and BrO 3 - D BC l3 and BeC l2 9 Which set of properties could apply to a non-ionic compound which has a giant lattice? Physical state at room temperature Electrical conductivity of the molten compound Melting point / o C A Liquid Does not conduct -114 B Liquid Does not conduct Melts over a temperature range C Solid Does not conduct 110 D Solid Does not conduct 1610

© ACJC 2007 9746/01/Prelim/07 4 10 The following graph shows how a property of the ele ments Na to C l varies with proton number. What is the property? A Electronegativity B First ionisation energy C Ionic radius D Melting point 11 Which of the following reacts most vigorously with cold water? A Sodium B Potassium C Magnesium D Calcium 12 The oxide and chloride of an element L are separately added to water. The two resulting solutions have the same effect on litmus paper. Which element could L be? A Sodium B Magnesium C Silicon D Phosphorus 13 The lattice energies of magnesium fluoride and calc ium chloride are − 2955 kJ mol -1 and −2255 kJ mol -1, respectively. Which of the following values is li kely to be the lattice energy of calcium fluoride? Na Mg A l Si P S C l

© ACJC 2007 9746/01/Prelim/07 [Turn over 5 A -2030 kJ mol -1 B -2640 kJ mol -1 C -3160 kJ mol -1 D -4080 kJ mol -1 14 The use of the Data Booklet is relevant to this question. Calculate the enthalpy change of reaction for CH 2=CHCH 3 (g) + Cl2 (g) → CH 2ClCHClCH 3 (g) A -86 kJ mol -1 B -176 kJ mol -1 C +174 kJ mol -1 D -316 kJ mol -1 15 Radioactive decay of Particle A to Particle B follows first order kinetics. After 3 half −lives have elapsed, the mole ratio of Particle A : Particle B would be A 1 : 2 C 1 : 7 B 1 : 3 D 1 : 8 16 When the following equilibrium is established. Cu (s) + 2 Ag + (aq) Cu 2+ (aq) + 2Ag (s) Which of the following is the correct expression for equilibrium constant Kc? A ][Ag ][Cu 2 + + B 2 2 ][Ag ][Cu + + C ][Cu][Ag ][Ag][Cu 2 + + D 2 22 ][Cu][Ag ][Ag][Cu + + 17 Given that the K c value for equilibrium I is 2.6, what is the Kc value for equilibrium II under the same condition?

© ACJC 2007 9746/01/Prelim/07 6 Equilibrium I: 4X (g) + Y 2 (g) 2X 2Y (g) Equilibrium II : X2Y(g) ½ Y 2 (g) + 2X (g) A 1.3 1 C 1.3 1 B 2.6 1 D 2.6 1 18 Consider the equilibrium, HSO 4 -(aq) + HPO 4 2-(aq) SO 4 2-(aq) + H 2PO 4 -(aq). Which of the following is a conjugate acid-base pair? Base Conjugate acid A HPO 4 2- HSO 4 - B HPO 4 2- H 2PO 4 - C HSO 4 - SO 4 2- D HSO 4 - HPO 4 2- 19 The following graph shows the changes in pH of 20.0 cm 3 of 1.0 mol dm -3 acid solution when excess 1.0 mol dm -3 alkali solution is added gradually. Which one of the following pairs of solution with a suitable indicator could have resulted in the graph below? acid alkali indicator A CH 3COOH NaOH Methyl orange B CH 3COOH NaOH Phenolphthalein C CH 3COOH Ba(OH) 2 Methyl orange D CH 3COOH Ba(OH) 2 Phenolphthalein 10 Volume of alkali added / cm 3

© ACJC 2007 9746/01/Prelim/07 [Turn over 7 20 What is the total number of sigma bonds in a molecu le of 2-methylpropene as shown below? C C H H CH3 CH3 A 5 C 11 B 6 D 12 21 Which of the following represents the molecular for mula of a compound that can exhibit geometric isomerism? A C2H6O2 C C2H2Cl2 B C2H3Cl D C 2H2O4 22 Which of the following isomers of C 5H12 O gives, on complete dehydration, the greatest number of different alkenes? A CH 3CH 2CH(CH 3)CH 2OH B CH 3CH 2CH 2CH(OH)CH 3 C CH 3CH(CH 3)CH 2CH 2OH D C(CH 3)3CH 2OH 23 Which of the following compounds, when dissolved in water, will give a solution of the lowest pH? (Assuming the solutions have the same concentration.) A Chloroethanoic acid B Propan-1-ol C Ethanoic acid D 2-Chloropropan-1-ol

© ACJC 2007 9746/01/Prelim/07 8 24 Ethene (M r = 28.0) reacts with a reagent R in the dark to form a compound Q (M r = 187.8). Which of the following statements is false about the reaction? A The reaction mechanism is electrophilic addition. B Q could be dibromoethane C The reagent R is HBr D The reaction can occur in the presence of light