MC 2021 Chem Paper 1A

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Nov 24, 2024

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METHODIST COLLEGE HONG KONG DIPLOMA OF SECONDARY EDUCATION EXAMINATION S.6 MOCK EXAMINATION CHEMISTRY PAPER 1 8: 30 11:00 a.m. (2 hours 30 minutes) 24 February 2021 This paper must be answered in English. GENERAL INSTRUCTIONS 1. There are TWO sections, A and B, in this Paper. You are advised to finish Section A in about 45 minutes. 2. Section A consists of multiple-choice questions in this question book, while Section B contains conventional questions printed separately in Question-Answer Book B . 3. Answers to Section A should be marked on the Multiple-choice Answer Sheet while answers to Section B should be written in the spaces provided in Question-Answer Book B. The Answer Sheet for Section A and the Question-Answer Book for Section B will be collected separately at the end of the examination. 4. A Periodic Table is printed on the last page of Question-Answer Book B . Atomic numbers and relative atomic masses of elements can be obtained from the Periodic Table. INSTRUCTIONS FOR SECTION A (MULTIPLE-CHOICE QUESTIONS) 1. Read the instructions on the Answer Sheet carefully. 2. Write your name, class and class number in the spaces provided. 3. When told to open this book, you should check that all the questions are there. Look for the words “ END OF SECTION A ” after the last question. 4. All questions carry equal marks. 5. ANSWER ALL QUESTIONS . You should use an HB pencil to mark all the answers on the Answer Sheet, so that wrong marks can be completely erased with a clean eraser. You must mark the answers clearly, otherwise you will lose marks if the answers cannot be captured. 6. You should write only ONE answer for each question. If you write more than one answer, you will receive NO MARKS for that question. 7. No marks will be deducted for wrong answers. 2021-DSE CHEM PAPER 1A
2020-2021 F.6 Chem Paper 1A Mock Exam/P.2 This section consists of two parts. There are 24 questions in PART I and 12 questions in PART II. Choose the best answer for each question. Candidates may refer to the Periodic Table printed on the back of Question-Answer Book B. PART I 1. Which of the following statements about a neutron is correct? A. Neutron has no electrical charges. B. Neutron is found in the nucleus of all atoms. C. Neutron weighs much less than a proton. D. Atoms of the same element must contain the same number of neutrons. 2. In the Periodic Table, the elements of the main group demonstrate a gradual change in some of their physical properties across the period. Which of the following statements is / are correct? (1) The melting point of element increases across the period. (2) The electronegativity of the main group elements increases across the period from Group I to Group VII. (3) The metallic character decreases across the period. A. (1) only B. (2) only C. (1) and (3) only D. (2) and (3) only 3. The formula of dimethyl ether is CH 3 OCH 3 . In a sample, 8.7% of the dimethyl ether molecules contain the O 8 18 isotope while the rest contain the O 8 16 isotope. What is the relative molecular mass of dimethyl ether in the sample? (Assume that the relative atomic masses of carbon and hydrogen in the dimethyl ether sample are 12.0 and 1.0 respectively.) A. 46.2 B. 46.8 C. 47.2 D. 47.8 4. Self-igniting flares contain magnesium phosphide (Mg 3 P 2 ). It reacts with water to produce diphosphane (P 2 H 4 ) which is flammable in air. Mg 3 P 2 + ?H 2 O → ?Mg(OH) 2 + ?P 2 H 4 + ?H 2 Which of the following combinations is correct? w x y z A. 3 3 2 2 B. 3 2 1 1 C. 6 2 2 2
2020-2021 F.6 Chem Paper 1A Mock Exam/P.3 D. 6 3 1 1 5. Which of the following observable changes can be made when adding a very small piece of sodium to 50 cm 3 of copper(II) sulphate solution? (1) Sodium dissolves in the solution. (2) A pale blue precipitate forms. (3) Colourless gas bubbles evolve. A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1), (2) and (3) 6. Which of the following observable changes can be made when a mixture of zinc and copper(II) oxide is heated strongly and then cooled? (1) Some white solid forms. (2) Some yellow solid forms. (3) Some reddish brown solid forms. A. (1) only B. (2) only C. (1) and (3) only D. (2) and (3) only 7. The following equation shows the decomposition of sodium hydrogencarbonate: 2NaHCO 3 (s) Na 2 CO 3 (s) + CO 2 (g) + H 2 O(l) What is the maximum mass of sodium carbonate that can be obtained from 0.10 mol of sodium hydrogencarbonate? (Relative atomic masses: C = 12.0, O = 16.0, Na = 23.0) A. 4.15 g B. 5.30 g C. 10.6 g D. 21.2 g 8. Which of the following statements concerning aluminium are correct? (1) Aluminium is used to make overhead power cables. (2) The strength of aluminium can be enhanced by anodization. (3) When aluminium is exposed to air, a layer of aluminium oxide is formed on its surface. A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1), (2) and (3)
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2020-2021 F.6 Chem Paper 1A Mock Exam/P.4 9. A student added dilute hydrochloric acid, dilute sodium hydroxide solution and water to the liquid extracts of four substances ( P , Q , R and S ). The results are shown in the table below. Liquid extracts Colour in water Colour in HCl Colour in NaOH P Pale pink Pale pink Orange Q Light purple Red Green R Green Purple Green S Yellow Yellow Yellow Which of the following liquid extracts is the most appropriate to be used as an acid-base indicator? A. P B. Q C. R D. S 10. 2.5 dm 3 of a hydrochloric acid is required to react completely with 100 g of a sample of calcium carbonate, which is 85% pure. What is the concentration of the hydrochloric acid? (Relative atomic masses: C = 12.0, O = 16.0, Ca = 40.1) A. 0.94 mol dm 3 B. 0.80 mol dm 3 C. 0.68 mol dm 3 D. 0.40 mol dm 3 11. Which of the following is NOT the appropriate substance for preparing zinc chloride by directly mixing it with dilute hydrochloric acid? A. zinc nitrate B. zinc carbonate C. zinc metal D. zinc oxide 12. Consider equal volumes of 1.0 mol dm –3 sodium hydroxide solution and 1.0 mol dm –3 aqueous ammonia. Which of the following statements about the solutions are correct? (1) Sodium hydroxide solution has a higher electrical conductivity than aqueous ammonia. (2) Sodium hydroxide solution has a higher hydrogen ion concentration than aqueous a ammonia. (3) Sodium hydroxide solution has a higher pH than aqueous ammonia. A. (1) and (2) only B. (1) and (3) only
2020-2021 F.6 Chem Paper 1A Mock Exam/P.5 C. (2) and (3) only D. (1), (2) and (3) 13. In an experiment, dilute H 2 SO 4 (aq) was added gradually to a fixed volume of dilute Ba(OH) 2 (aq). The change in a certain parameter of the mixture was measured. The graph below shows the results of the experiment. What is the parameter? A. Electrical conductivity B. Volume C. Temperature D. Mass 14. The structures of organic compounds X and Y are shown below: Which of the following statements concerning the two compounds is correct? A. X and Y have the same empirical formula. B. X and Y are both soluble in water. C. X and Y can be distinguished by Br 2 (in CH 3 CCl 3 ). D. Complete combustion of 1.0 g of X and complete combustion of 1.0 g of Y would form the same mass of CO 2 (g). 15. Four alkanes, E , F , G and H , were obtained by fractional distillation of petroleum. Some of the properties of the four alkanes are shown below. (1) H is more viscous than F . (2) E is less flammable than H . (3) G burns with a less sooty flame than F and H . Which of the following is the correct order for which the four alkanes were collected from fractional distillation? First Last
2020-2021 F.6 Chem Paper 1A Mock Exam/P.6 A. F H E G B. E F H G C. G F H E D. E G F H 16. Consider the following statements and choose the best answer: 1st statement 2nd statement When using a Bunsen burner with the air hole fully open, the burner gives a luminous flame. When using a Bunsen burner with the air hole fully open, the fuel undergoes complete combustion. A. Both statements are true and the 2nd statement is a correct explanation of the 1st statement. B. Both statements are true but the 2nd statement is NOT a correct explanation of the 1st statement. C. The 1st statement is false but the 2nd statement is true. D. Both statements are false. 17. Chlorine reacts with 1-chloropropane in the presence of ultraviolet radiation. Which of the following equations shows an appropriate propagation step of the reaction? A. B. C. D. 18. Which of the following statements about fossil fuels is correct? A. They must be liquids or gases. B. They can cause air pollution when burnt. C. They can be recycled to help conserve energy resources. D. They are all formed from plants which died millions of years ago.
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2020-2021 F.6 Chem Paper 1A Mock Exam/P.7 19. Which of the following statements concerning a hydrogen-oxygen fuel cell is INCORRECT? A. Hydrogen gas is reduced during discharge. B. It produces a non-polluting product. C. Oxygen gas is supplied into the cathode. D. It contains a catalyst. 20. The following chemical reaction takes place in a silver oxide cell. Ag 2 O(s) + Zn(s) + H 2 O(l) 2Ag(s) + Zn(OH) 2 (s) What is the role of silver oxide in the cell? A. It is the negative electrode and the oxidizing agent. B. It is the positive electrode and the oxidizing agent. C. It is the negative electrode and the reducing agent. D. It is the positive electrode and the reducing agent. 21. The diagram below shows an experimental set-up a student used to plate a steel handle with copper. However, the experiment was unsuccessful. Which of the following changes is necessary to plate the steel handle with copper? A. Make the steel handle the cathode. B. Use iron(II) sulphate solution as the electrolyte. C. Increase the current. D. Increase the concentration of copper(II) sulphate in the solution. 22. To which of the following chemical species is / are the ‘octet rule’ applicable? (1) BF 3 (2) CS 2 (3) SF 6 A. (1) only B. (2) only C. (1) and (3) only D. (2) and (3) only 23. The formation of liquid water from hydrogen and oxygen may occur in three stages. Stage 1 2H 2 (g) + O 2 (g) 4H(g) + 2O(g)
2020-2021 F.6 Chem Paper 1A Mock Exam/P.8 Stage 2 4H(g) + 2O(g) 2H 2 O(g) Stage 3 2H 2 O(g) 2H 2 O(l) Which of the stages is /are endothermic? A. Stage 1 only B. Stage 2 only C. Stages 1 and 3 only D. Stages 2 and 3 only 24. The table below lists the standard enthalpy changes of combustion of three substances. Substance ∆𝑯 𝐜 𝐎 (kJ mol –1 ) C 6 H 12 O 6 (s) glucose –2 803 C(graphite) –394 H 2 (g) –286 What is the standard enthalpy change of formation of glucose? A. +2 993 kJ mol –1 B. +1 277 kJ mol –1 C. –1 277 kJ mol –1 D. –2 993 kJ mol –1 PART II 25. Which of the following statements concerning a catalyst is INCORRECT? A. A catalyst must be in the same physical state as the reactants. B. The mass of a catalyst remains unchanged at the end of the reaction. C. A catalyst can alter the rate of a reaction. D. A catalyst remains chemically unchanged at the end of the reaction. 26. In an experiment, X (g) was allowed to decompose to give Y (g) and Z (g) in a closed vessel of constant volume. The graph below shows how the concentration of X , Y and Z varied with time at constant temperature.
2020-2021 F.6 Chem Paper 1A Mock Exam/P.9 Which of the following is the chemical equation for the decomposition of X (g)? A. X (g) Y (g) + Z (g) B. 2 X (g) Y (g) + Z (g) C. X (g) 2 Y (g) + Z (g) D. 2 X( g) 2 Y (g) + Z (g) 27. Methoxymethane (CH 3 OCH 3 ) is used as a propellant in spray cans. It can be produced from methanol according to the equation below. 2CH 3 OH(g) CH 3 OCH 3 (g) + H 2 O(g) The equilibrium constant, K c , for this reaction is 5.76 at 350 °C. In an experiment, a 10.0 dm 3 closed container initially contained 1.50 moles of CH 3 OH(g), 4.00 moles of CH 3 OCH 3 (g) and 5.00 moles of H 2 O(g) at 350 °C. Which of the following combinations is correct at that moment? Reaction quotient Q c (mol dm –3 ) Rate of the reaction A. 8.89 forward > backward B. 8.89 backward > forward C. 0.0750 forward > backward D. 0.0750 backward > forward 28. Consider the following two reversible reactions. Reaction I : X 2 (g) + 2 1 Y 2 (g) X 2 Y (g) Reaction II : 2 X 2 Y (g) 2 X 2 (g) + Y 2 (g) The numerical value of K c for reaction I is 2. Under the same conditions, what is the numerical value of K c for reaction II ? A. 2 1 B. 2 1 C. 4 1 D. 4 29. 2-chloro-2-methylpropane is prepared by shaking methylpropane-2-ol and excess concentrated hydrochloric acid in a separating funnel. (CH 3 ) 3 COH 𝑐??𝑐.𝐻𝐶𝑙 (CH 3 ) 3 CCl Which of the following statements about this preparation is INCORRECT? A. Two layers of liquid can be observed in the separating funnel after shaking.
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2020-2021 F.6 Chem Paper 1A Mock Exam/P.10 B. The crude product should be washed with sodium hydrogencarbonate solution. C. The crude product can be dried by anhydrous calcium chloride. D. The unreacted methylpropan-2-ol can be removed by simple distillation. 30. Cortisone is one of the main hormones in our body. It has the following structure: Which of the following statements about cortisone are correct? (1) It has a hydroxyl group for tertiary alcohol. (2) It can change acidified potassium dichromate solution from orange to green. (3) It has three ketone groups. A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1), (2) and (3) 31. In an experiment, cyclohexanol is heated with concentrated phosphoric acid to give an unsaturated compound in the set-up shown below. Which of the following statements about the experiment are correct?
2020-2021 F.6 Chem Paper 1A Mock Exam/P.11 (1) Cyclohexanol undergoes dehydration. (2) Cyclohexanol loses its chiral centre after the reaction. (3) Concentrated sulphuric acid can be used instead of concentrated phosphoric acid. A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1), (2) and (3) 32. Consider the following conversion of organic compounds: Which of the following statements are correct? (1) Light is needed in Step 1 . (2) The reagent used in Step 1 is HBr(g). (3) The reagent used in Step 2 can be KOH(aq). A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1), (2) and (3) 33. Aspirin is widely used as a painkiller. It may be produced from salicylic acid. The structure of aspirin and salicylic acid are shown below. Which of the following statements about aspirin is/are correct? (1) It may be prepared by the reaction between salicylic acid and CH 3 OH. (2) It contains an ester functional group. (3) It can react with NaHCO 3 (aq).
2020-2021 F.6 Chem Paper 1A Mock Exam/P.12 A. (1) only B. (2) only C. (1) and (3) only D. (2) and (3) only
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2020-2021 F.6 Chem Paper 1A Mock Exam/P.13 34. E , F and G are oxides of Period 3 elements. Three experiments are conducted on each oxide. The results of the experiments are shown in the table below: Oxide Solubility in water Adding the oxide to dilute HCl(aq) Adding the oxide to dilute NaOH(aq) E Soluble pH increases No change in the pH F Insoluble pH increases pH decreases G Soluble No change in the pH pH decreases Which of the following statements are correct? (1) E and F are metal oxides while G is a non-metal oxide. (2) F is an amphoteric oxide. (3) Among the three oxides, G has the lowest melting point. A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1), (2) and (3) 35. Element P can undergo the following reactions: Which of the following statements about element P are correct? (1) P must be a transition metal which can form compounds of variable oxidation states. (2) P may be iron. (3) Q is an oxidizing agent. A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1), (2) and (3) 36. Consider the following statements and choose the best answer: 1st statement 2nd statement Nylon-6,6 is a polymer formed from the reaction between hexanediamide and hexanediol. Nylon-6,6 is a condensation polymer. A. Both statements are true and the 2nd statement is a correct explanation of the 1st statement. B. Both statements are true but the 2nd statement is NOT a correct explanation of the 1st statement. C. The 1st statement is false but the 2nd statement is true. D. Both statements are false. END OF SECTION A P PQ n PQ m Q Q where m > n
2020-2021 F.6 Chem Paper 1A Mock Exam/P.14