NYGH 2015-S3MYE-Chem

Class Register Number Name 南洋女子中学校 NANYANG GIRLS’ HIGH SCHOOL Mid-Year Examination 2015 Secondary Three CHEMISTRY 1 hour 30 minutes Theory Paper 0800h-0930h Wednesday 13 May 2015 Additional materials: Writing papers READ THESE INSTRUCTIONS FIRST Do not open this booklet until you are told to do so. Write your name, register number and class in the spaces at the top of this page. Section A (MCQ) Write your name, class and register number on the Multiple Choice Answer Sheet provided. There are twenty 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 answer sheet. Section B (Structured) Answer All questions in the spaces provided on the Question Paper. Section C (Free-Response) Answer All questions. Write your answers on the separate writing paper provided. Submit Multiple Choice Answer Sheet, Question Paper and Writing Paper separately. The intended number of marks is given in the brackets [ ] at the end of each question or part question. A copy of the Periodic Table is printed on page 13. Examiner’s Use Section A (20 marks) Section B (30 marks) Section C (10 marks) Total (60 marks) Setters: CHG, LSC This document consists of 13 printed pages. NANYANG GIRLS’ HIGH SCHOOL [Turn over]

2015 Mid-Year Examination Secondary Three 2 Nanyang Girls’ High School Setters: CHG, LSC Chemistry Section A (20 marks) 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 answer sheet. 1 Which of the following salts is prepared using titration? A aluminium chloride B ammonium nitrate C lead(II) sulfate D iron(II) chloride 2 Which of the following is NOT true? A Hydrogen chloride gas turns moist blue litmus paper red. B Sulfur dioxide gas turns dry blue litmus paper red. C An acid only shows its acidic properties in the presence of water. D Acid molecules ionize in the presence of water to produce hydrogen ions. 3 Which one of the following compounds will not increase the pH of an acidic solution? A calcium oxide C calcium hydroxide B calcium carbonate D calcium sulfate 4 Which of the following is the correct ionic equation for the formation of an insoluble salt? A Ag+(aq) +Cl - (aq)  AgCl(s) B Na+(aq) + NO3 -(aq)  NaNO3(s) C 2K+(aq) + SO4 2-(aq)  K2SO4(s) D Pb2+(aq) + 2NO3 -(aq)  Pb(NO3)2(s) 5 Which of the following gives ONLY a colourless solution when reacted with dilute hydrochloric acid? A barium carbonate C potassium hydroxide B copper(II) oxide D zinc metal 6 Ant bites are acidic in nature. Which of the following is suitable for treating it? A vinegar C sugar B baking powder D orange juice 7 Aluminium hydroxide is a base. Why is it used in the manufacture of toothpaste? A It helps to whiten teeth. B It helps to strengthen teeth. C It kills the bacteria in the mouth. D It prevents tooth decay by neutralising the acids produced by bacteria in the mouth.

2015 Mid-Year Examination Secondary Three 3 Nanyang Girls’ High School Setters: CHG, LSC Chemistry [Turn Over] 8 2 drops of methyl orange are added to 15 cm3 of dilute nitric acid in a conical flask. 10 cm3 of aqueous sodium hydroxide of similar concentration are then added gradually to the flask. What change occurs in the mixture in the conical flask? A Methyl orange changes colour from yellow to red. B A gas is formed. C The pH value is increased. D The concentration of the H+ ion increases. 9 Which of the following pairs of solutions when added together will produce a precipitate? I Potassium carbonate and silver nitrate II Lead(II) nitrate and sodium chloride III Sodium carbonate and copper(II) sulfate IV Magnesium chloride and barium nitrate A I and II only C I, II and III only B I, II and IV only D I, II, III and IV 10 Ian soaked his feet in a pail filled with vinegar. When he stepped onto the marble floor, he observed that there were bubbles of gas around his feet. What is the identity of the gas produced? A hydrogen C oxygen B carbon dioxide D ammonia 11 Which of the following must be true of an acidic salt? A It turns damp blue litmus paper red. B It is the only salt formed from a dibasic acid. C It contains hydrogen that is replaceable by a metal. D It is a salt of a non-metal. 12 Which of the following methods listed below cannot be used to prepare the respective solid salt? Method Solid salt A Add hydrochloric acid to lead(II) carbonate. lead(II) chloride B Add aqueous sodium carbonate to aqueous magnesium nitrate. magnesium carbonate C Add aqueous barium nitrate to sulfuric acid. barium sulfate D Add nitric acid to silver carbonate, then add aqueous sodium iodide. silver iodide

2015 Mid-Year Examination Secondary Three 4 Nanyang Girls’ High School Setters: CHG, LSC Chemistry 13 The apparatus below was used to examine an air sample. It was found that the anhydrous cobalt chloride turned from blue to pink, the acidified aqueous potassium manganate(VII) turned from purple to colourless and a white precipitate was formed in the aqueous calcium hydroxide. Wh at gases were present in the air sample? A H2O, SO2, CO2 C CO2, H2O, H2 B H2O, SO2, NO D O2, H2, NO2 14 Solution S reacts with aqueous sodium hydroxide to form a white precipitate that is insoluble in excess aqueous sodium hydroxide. Identify the cations that are likely to be in solution S. I Lead(II) ion II Calcium ion III Aluminium ion IV Iron(II) ion A II only C II and IV only B IV only D I, II, III and IV 15 Aqueous sodium hydroxide and a piece of aluminium foil were added to a colourless solution X. The mixture was warmed and a pungent gas which turned moist red litmus blue was evolved. What could X be? A Silver nitrate C Sodium iodide B Iron(III) nitrate D Zinc sulfate Anhydrous cobalt chloride Aqueous calcium hydroxide Acidified potassium manganate(VII) Air sample To air pump

2015 Mid-Year Examination Secondary Three 5 Nanyang Girls’ High School Setters: CHG, LSC Chemistry [Turn Over] 16 The following tests were conducted on solution P separately. The observations are as tabulated: Tests Observation Add excess aqueous sodium hydroxide to 1 cm3 of solution P gradually. White precipitate was observed. The white precipitate was soluble in excess aqueous sodium hydroxide. Add excess aqueous ammonia to 1 cm3 of solution P gradually. White precipitate was observed. The white precipitate was insoluble in excess aqueous ammonia. What could solution P be? A lead(II) sulfate C zinc sulfate B aluminium sulfate D ammonium sulfate 17 Dilute nitric acid was added to compound Q to give a gas and a colourless solution R. Aqueous ammonia was then added to the solution R to give a white precipitate which dissolved in excess aqueous ammonia to form a colourless solution. What could compound Q be? A lead(II) carbonate C copper(II) carbonate B zinc carbonate D calcium carbonate 18 Which of the following reagents when added separately to aqueous lead(II) nitrate and aqueous aluminium nitrate will be able to distinguish the two solutions? A hydrochloric acid C aqueous sodium hydroxide B nitric acid D aqueous ammonia 19 Which of the following procedures will NOT produce a colourless and pungent gas which turns moist red litmus paper blue? A ammonium chloride is warmed with aqueous sodium hydroxide B sodium chloride is warmed with aqueous ba