1、香港理工大学化学习题Secondary School Mathematics & Science Competition 2018ChemistryDate: 11th May 2018Total no. of pages: 18Time allowed: 11:45 am - 1:00 pm (1hour 15 minutes)Total marks: 751. Write your Candidate Number, Centre Number, Name (both in English and Chinese), Name of School, Form, Date, Gender,
2、Language and Subject in the spaces provided on the MC Answer Sheet and the Part B Answer Sheet.2. When told to open this question paper, you should check that all the questions are there. Look for the words END OF PAPER after the last question.3. Answer ALL questions in Part A. You are advised to us
3、e an HB pencil to mark your answers on the MC Answer Sheet.4. You should mark only ONE answer for each question in Part A. If you mark more than one answer, you will receive NO MARK for that question.5. There are SIX questions in Part B. Answer ANY FIVE questions. You should write your answer on the
4、 Part B Answer Sheet.6. A Periodic Table is provided on the last page of the question paper.7. No mark will be deducted for wrong answers.8. The diagrams in the paper are not necessarily drawn to scale. The Hong Kong Polytechnic University 2018 All Rights Reserved.Part A: Multiple Choice questions (
5、Answer ALL questions in this part)1. Which of the following substances is / are liquid(s) at 0oC?SubstanceMelting point (C)Boiling point (C)W-20054X-120-10Y50320Z-10013A. X onlyB. W onlyC. W and Z onlyD. Y and Z only2. Which of the following methods can be used to distinguish between solid calcium h
6、ydrogencarbonate and solid potassium hydrogen carbonate?I. Add dilute sulphuric acid.II. Perform a flame test.III. Dissolve the solids in water.A. (I) onlyB. (II) onlyC. (I) and (II) onlyD. (II) and (III) onlyRefer to the following diagram for questions 3 and 4:calcium carbonateheatsolid X+ gas Y+ w
7、atersolution Z3. What could solid X and solution Z be?solid Xsolution ZA.calcium oxidecalcium hydroxideB.calcium hydroxidecalcium oxideC.calcium chloridecalcium hydroxideD.calcium oxidecalcium chloride14. What would be observed if gas Y is bubbled into solution Z until in excess?A. Effervescence occ
8、urs.B. Solution Z turns milky and then clear.C. Solution Z becomes yellow in colour.D. There is no observable change.5. An atom of element A has the following electronic structure:To which group and period of the Periodic Table does element A belong?GroupPeriodA.II3B.VI3C.II4D.VI46. The chemical pro
9、perties of an element depend onA. its melting point.B. its relative atomic mass.C. the number of occupied electron shells in its atom.D. the number of outermost shell electrons in its atom.7. Which of the following statements concerning chlorine, bromine and iodine is INCORRECT?A. They are all poiso
10、nous.B. They are all coloured.C. They can react with sodium sulphate solution to form a colourless solution.D. All of them are oxidizing agents.28. Which of the following species has the same number of electrons as ammonium ion?A. CO32-B. K+C. H2OD. NaCl9. Solid zinc sulphide cannot conduct electric
11、ity becauseA. zinc conducts electricity but sulphur does not.B. it is a non-electrolyte.C. the ions are not mobile.D. it is a covalent compound.10. Ionic compounds have high melting points becauseA. the attractions between the electrons and the ions are strong.B. the attractions between the ions are
12、 strong.C. The ions are packed regularly in crystals.D. ionic compounds are made of metals having high melting points.11. C60 molecule is a form of solid carbon as shown below:Which of the following statement(s) is / are correct?I. The solid has high electrical conductivity.II. The solid gives carbo
13、n dioxide upon complete combustion.III. The solid has a giant covalent structure.A. (I) onlyB. (II) onlyC. (I) and (III) onlyD. (II) and (III) only312. Which of the following compounds does NOT follow the octet rule?A. CO2B. NO2C. Cl2OD. H2O13. Which of the following combinations concerning the numb
14、ers of electron pairs in the outermost shell of the sulphur atom in a SF6 molecule is CORRECT?Number of bond pair(s)Number of lone pair(s)A.60B.42C.24D.0614. Which of the following is a polar compound?A. CH4B. CO2C. PCl5D. NH315. Consider the half equation below:ClO3(aq) + a H2O(l) + b e Cl(aq) + c
15、OH(aq)Which of the following combinations of a, b and c is CORRECT?abcA.122B.244C.366D.488416. Consider the following flow diagram:CuO(s) reactant A Cu(s) reactant B Cu2+ (aq)Which of the following combinations is CORRECT?Reactant AReactant BA.C(s)concentrated HCl(aq)B.H2(g)dilute H2SO4(aq)C.CO(g)di
16、lute HNO3(aq)D.NaOH(aq)dilute HCl(aq)17.According to the above setup, which of the following statements is CORRECT?A. Metal A is the positive electrode.B. Copper is more reactive than metal A.C. The mass of the copper electrode decreases.D. The mass of the metal A decreases.518. In the following set
17、up, metal B is less reactive than metal A.Which of the following statement(s) concerning this setup is/are CORRECT?I. Electrolysis occurs inside the lemonII. Chemical energy is changed into electrical energyIII. Electrons flow from metal B to metal A in the external circuitA. (I) onlyB. (II) onlyC.
18、(I) and (III) onlyD. (II) and (III) only19.In the above experiment, which of the following major products will be liberated at the electrodes?CathodeAnodeA.zincoxygenB.zincchlorineC.hydrogenchlorineD.hydrogenoxygen620. Menthol is an important organic compound obtained from peppermint.How many chiral
19、 centre(s) are there in the molecule of menthol?A. 1B. 2C. 3D. 421. Which of the following combinations would react to produce the ester “CH3CH2C(O)OCH3”?A. methanol and propanoic acidB. propan-1-ol and methanoic acidC. propan-2-ol and methanoic acidD. ethanol and ethanoic acid22. 50.0 cm3 of 1.00 m
20、ol dm-3 HA was added to 50.0 cm3 of 1.00 mol dm-3 potassium hydroxide solution. A temperature rise of T oC was observed. What is the enthalpy change of neutralization (in kJ mol-1)? (Assume the specific heat capacity of the resulting solution = 4.18 J g-1 K-1 and density = 1.0 g cm-3)A. (50.0 x 4.18
21、 x T) / 1000B. (100.0 x 20.0 x T) / (1000 x 4.18)C. (100.0 x 20.0 x 4.18) / (1000 x T)D. (100.0 x 20.0 x 4.18 x T) / (1000)723. A substance Z was formed by the reaction between substance X and Y at a constant temperature at the rates given below:Concentration of X /mol dm-3Concentration of Y /mol dm
22、-3Rate of formation of Z /mol dm-3 s-11.50 10-14.00 10-21.20 10-22.25 10-14.00 10-21.80 10-21.50 10-12.00 10-23.00 10-3Which of the following equation is the rate equation for the above reaction?A. Rate = kXYB. Rate = kXY2C. Rate = kX2Y2D. Rate = kX2Y224. When marble chips reacted with an excess of
23、dilute hydrochloric acid in a conical flask, the progress of the reaction was studied and measured. A graph was plotted over a period of 5 minutes after starting of the reaction, and the reaction was completed in 2.5 minutes. Which of the following would be the y-axis for the graph?Time (min)A. Tota
24、l mass of the conical flask and its contentsB. Volume of carbon dioxide producedC. Electrical conductivity of solutionD. Temperature of solution825. The conversion of sulphur dioxide to sulphur trioxide in the Contact Process involves the following:2SO2(g) + O2(g) 2SO3(g) HO = 197 kJ mol-1Which of t
25、he following action(s) would increase the production of sulphur trioxide?I. Increase the temperature of the systemII. Increase the total pressure of the system III. Add positive catalyst to the systemA. (II) onlyB. (III) onlyC. (I) and (III) onlyD. (II) and (III) only26. Which of the following is th
26、e most appropriate way of diluting concentrated sulphuric acid?A. Pour the acid into water slowly with constant stirring.B. Pour water into the acid slowly with constant stirring.C. Pour the acid into water as quickly as possible.D. Pour water into the acid as quickly as possible.27. In an experimen
27、t, a student put a coin into a beaker of silver nitrate solution. Soon later, the surface of the coin was covered by a grey layer. Which of the following CONCLUSION about the experiment isCORRECT?A. That coin contained a kind of metal which can be oxidized.B. That coin is a copper coin.C. That coin
28、is a gold coin.D. That coin contained a kind of metal which was more reactive than silver.928. After the titration experiment, the burette containing dilute sodium hydroxide solution should be washed withA. dilute hydrochloric acid only.B. distilled water only.C. distilled water and then dilute hydr
29、ochloric acid.D. dilute hydrochloric acid and then distilled water.29. In a solution containing sodium chloride and sodium carbonate, the concentration of sodium ions and chloride ions are 0.5 M and 0.2 M, respectively. What is the concentration of carbonate ions?A. 0.10 MB. 0.15 MC. 0.20 MD. 0.30 M30. 17.8 cm3 of 0.5 M sulphuric acid solution can completely neutralize 25.0 cm3 potassium hydroxide solution. What is the molarity of the potassium hydroxide solution?A. 0.356 MB. 0.702 MC. 0.712 MD. 1.42 M31. Which of the following would exhibit periodicity across a period?I. N
