2021 ACSI Prelims Paper 1

1 Anglo-Chinese School (Independent) 6092/1 Year 4 Express Preliminary Exam 2021 [Turn over Anglo-Chinese School (Independent) Year 4 Express Preliminary Examination 2021 CHEMISTRY PAPER 1 Multiple Choice 6092/1 Tuesday 17th August 2021 1 hour Additional materials: Calculator Multiple Choice answer sheet Soft clean eraser Soft pencil (type 2B recommended) INSTRUCTIONS TO CANDIDATES Do not open this booklet until you are told to do so. Write and shade the candidate number on the answer sheet in the spaces provided. There are forty questions in 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. INFORMATION FOR CANDIDATES 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. You may use a calculator. A copy of the Periodic Table is printed on page 16. This question paper consists of 16 printed pages.

2 Anglo-Chinese School (Independent) 6092/1 Year 4 Express Preliminary Exam 2021 [Turn over 1 The boiling points of various gases found in a gas sample are shown below. gas boiling point / oC argon - 186 oxygen - 183 nitrogen - 198 Which gas(es) will remain gas(es) in the gas sample at – 185oC? A nitrogen only B oxygen only C argon and nitrogen only D oxygen and nitrogen only 2 Which of the following apparatus will be most suitable to measure accurately 14.8 cm 3 of dilute nitric acid? A B C D

3 Anglo-Chinese School (Independent) 6092/1 Year 4 Express Preliminary Exam 2021 [Turn over 3 When a beaker full of ethene is inverted over a porous pot containing carbon monoxide as shown in the diagram below, the water level does not move. This is because both gases ________________________________. A are carbon compounds B are miscible C do not dissolve in water D have the same relative molecular mass 4 A mobile phone with a stainless steel casing contains the neurotoxin mercury and the carcinogen gallium arsenide. Which row correctly classifies the materials found in the phone casing? element mixture compound A mercury gallium arsenide stainless steel B mercury stainless steel gallium arsenide C stainless steel gallium arsenide mercury D stainless steel mercury gallium arsenide water beaker ethene carbon monoxide porous pot

4 Anglo-Chinese School (Independent) 6092/1 Year 4 Express Preliminary Exam 2021 [Turn over 5 The nucleon number of an ion X3+ is 27 and it has 10 electrons. What does the nucleus of the ion X3+ contains? number of protons number of neutrons A 7 20 B 10 17 C 13 14 D 14 13 6 Particle X has 3 protons, 4 neutrons and 3 electrons. Particle Y has 3 protons, 4 neutrons and 2 electrons. Which statement best describes particle Y? A Particle X and particle Y are atoms of the same element. B Particle Y has a larger relative atomic mass than particle X. C Particle Y is an ion of particle X. D Particle Y is an isotope of particle X. 7 Which substance contains the same number of atoms as 1 g of hydrogen gas? (All volumes are measured at room temperature and pressure.) A 0.5 mol of neon gas B 24 dm3 of chlorine gas C 48 g of ozone gas D 3 x 1023 oxygen molecules 8 Silver ions react with chloride ions as shown in the equation below. Ag+ (aq) + Cl- (aq) → AgCl (s) It is found that 5 cm 3 of 0.1 mol/dm3 solution of the chloride of metal X requires 10 cm 3 of 0.1 mol/dm3 silver nitrate for complete reaction. What is the formula of the chloride? A XCl4 B XCl2 C XCl D X2Cl

5 Anglo-Chinese School (Independent) 6092/1 Year 4 Express Preliminary Exam 2021 [Turn over 9 The compound SO2Cl2 reacts with water and is represented by the equation below. SO2Cl2 + 2H2O → H2SO4 + 2HCl How many moles of sodium hydroxide will be needed to neutralize the solution produced by one mole of SO2Cl2 and excess water? A 1 B 2 C 3 D 4 10 Which of the sets of substances contains an element, a mixture and a compound? A iron, steel, rust B diamond, coal, seawater C sodium, sodium hydroxide, sodium chloride D hydrogen, air, petroleum 11 How many non-bonding pair(s) of electrons are there in one molecule of methane, CH4? A 0 B 1 C 2 D 3 12 Which of the following is characteristic of all bases? A All bases contain oxide or hydroxide ions. B All bases react with neutral oxides. C All bases dissolve in water to produce solutions of pH about 7. D All bases react with ammonium salts to produce ammonia gas.

6 Anglo-Chinese School (Independent) 6092/1 Year 4 Express Preliminary Exam 2021 [Turn over 13 A black powder is burnt in air. The gas produced dissolves in water to form solution R. The difference between the pH of solution R and pure water is very small. The gas is readily absorbed in aqueous sodium hydroxide. What type of substance is present in solution R? A strong acid B strong base C weak acid D weak base 14 Which of the following reactions shows calcium hydroxide undergoing a precipitation reaction? A Ca(OH)2 + Na2SO4 → CaSO4 + 2NaOH B Ca(OH)2 + 2NO2 + O2 → Ca(NO3)2 + H2O C Ca(OH)2 + 2HCl → CaCl2 + H2O D Ca(OH)2 + 2NH4NO3 → Ca(NO3)2 + 2H2O + 2NH3 15 A reddish brown precipitate was produced when an excess of aqueous sodium hydroxide was added dropwise to solution B. In another experiment, a white precipitate was produced when dilute nitric acid and aqueous barium nitrate were added to solution B. What is the identity of solution B? A iron(II) chloride B iron(II) sulfate C iron(III) chloride D iron(III) sulfate

7 Anglo-Chinese School (Independent) 6092/1 Year 4 Express Preliminary Exam 2021 [Turn over 16 The diagrams below show three different experiments involving ammonium compounds. In which experiment(s) is/are ammonia formed? A 1 only B 2 only C 3 only D 1, 2 and 3 17 Hydrogen reacts with chlorine in an exothermic reaction. H2 (g) + Cl2 (g) → 2HCl (g) ∆H = - 184 kJ Why does ∆H for this reaction have a negative sign? A The total energy released in bond breaking is greater than the total energy absorbed in bond forming. B The total energy absorbed in bond breaking is greater than the total energy released in bond forming. C The total energy absorbed in bond breaking is less than the total energy released in bond forming. D The total energy released in bond breaking is less than the total energy released in bond forming. aqueous ammonium carbonate + dilute sulfuric acid aqueous ammonium nitrate + aqueous sodium nitrate aqueous ammonium chloride + dilute sodium hydroxide heat heat heat 1 2 3

8 Anglo-Chinese School (Independent) 6092/1 Year 4 Express Preliminary Exam 2021 [Turn over 18 Methane undergoes combustion in the equation given below. CH4 (g) + 2O2 (g) → CO2 (g) + 2H2O (g) bond bond energy kJ/mol O - O 142 O = O 494 C - H 435 C - O 358 C = O 799 O - H 464 What is the enthalpy change of the reaction? A + 507 kJ/mol B + 1001 kJ/mol C - 548 kJ/mol D - 726 kJ/mol 19 How are respiration, combustion and rusting similar? A They are all enzyme-driven processes. B They all require oxygen to be present. C They are highly endothermic processes. D They all require water to be presen