NYGH 2010-S3BT2-Chem

Class Register Number Name 南洋女子中学校 NANYANG GIRLS' HIGH SCHOOL BLOCK TEST 2 Secondary Three CHEMISTRY 1 hour Wednesday 4 August 2010 0745-0845 h 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 (Multiple Choice) Section A (15 MCQ) This section consists of 15 multiple choice questions. Choose the best answer and write its letter in the space provided on page 6 of the Question Paper. Section B (Structured) Answer All questions in the spaces provided on the Question Paper. Section C (Free-Response) Answer All questions in the spaces provided on the Question Paper. Submit Sections A, B and C together. INFORMATION FOR CANDIDATES 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. Topics: 1. Acids, Bases & Salts 2. Chemical Calculations (except Solution Concentration) Examiner’s Use Section A (15 marks) Section B (20 marks) Section C (10 marks) Total (45 marks) Setter: LaiSC This document consists of 13 printed pages. NANYANG GIRLS' HIGH SCHOOL [ Turn over]

2010 Secondary Three Block Test 2 Nanyang Girls’ High School Setter: LaiSC Chemistry 2 Section A (15 marks) Choose the most suitable answer and write its letter in the answer table provided on Page 5. 1 Acid Q is used to prepare two soluble salts, as shown below. + Æ + Æ Which of the following contains correct names for Q, R and S? Q R S A Hydrochloric acid Magnesium chloride Copper(II) chloride B Sulfuric acid Magnesium nitrate Copper(II) sulfate C Hydrochloric acid Magnesium hydroxide Copper(II) chloride D Sulfuric acid Magnesium oxide Copper(II) sulfate Acid Q Base R Magnesium sulfate Copper(II) oxide Salt S Acid Q 2 Which of the following is the correct ra tio of the number of atoms in 112 g of gaseous nitrogen to the number of atoms in 90 g of ethane (C 2H6)? A 1 : 1 C 1 : 6 B 1 : 3 D 1 : 12 3 The formula of a sodium compound in silica gel is Na 2Si4Ox. What is the value of x if the relative molecular mass of the sodium compound is 302? A 8 C 10 B 9 D 12 4 5 g of element X reacted with 8 g of element Y to form a compound with the formula XY2. Given that 80 is the relative atomic mass of Y, what is the relative atomic mass of X? A 25 C 40 B 50 D 100 5 Which of the following has the largest number of atoms? A 0.1 mole of oxygen B 0.2 mole of water C 0.3 mole of carbon D 0.4 mole of helium

2010 Secondary Three Block Test 2 Nanyang Girls’ High School Setter: LaiSC Chemistry [Turn Over] 3 6 Zinc oxide is produced by heating zinc carbonate. ZnCO3 Æ ZnO + CO2 What is the percentage yield of zinc oxide if 125 g zinc carbonate on heating produces 75 g of zinc oxide given that Mr of ZnCO3 is 125 and Mr of ZnO is 81? A 75/81 x 100 C 125 x 75/81 x 100 B 81/75 x 100 D 125 x 81/75 x 100 7 An organic compound contains 24 g of carbon, 4 g of hydrogen and 32 g of oxygen. What is the empirical formula of the compound? A CHO C CH 2O B CH4O D C2H4H2 8 Ammonia reacts with chlorine according to the equation below: 2NH3(g) + 3C l2(g) Æ N 2(g) + 6HCl(g) If 90 cm 3 of ammonia is mixed with 150 cm 3 of chlorine and al l the volumes are measured at the same tem perature and pressure, what is the total volume of the resultant mixture? A 315 cm3 C 350 cm3 B 330 cm3 D 365 cm3 9 The element X forms a gaseous molecule X2. One volume of X2 combines with two volume of hydrogen gas to form two volumes of a gaseous hydride. What is the formula for the hydride of X? A HX C H2X B HX2 D H2X2 10 Which of the following substances in wate r is most suitable to react with dilute hydrochloric acid to prepare silver chloride? A Silver oxide C Silver nitrate B Silver metal D Silver carbonate 11 Which of the following pairs of solu tions when added toget her will produce an insoluble salt? I Magnesium fluoride and lead(II) nitrate II Sodium chloride and silver nitrate III Copper(II) sulfate and barium chloride IV Potassium carbonate and sodium nitrate A I and II only C I, II and IV only B I, II and III only D I, II, III and IV

2010 Secondary Three Block Test 2 Nanyang Girls’ High School Setter: LaiSC Chemistry 4 12 An aqueous solution containing an anion ha s the following observation when the test is carried out on it. Test Observation Add aqueous barium chloride to the solution followed by dilute hydrochloric acid Form a white precipitate which is insoluble in dilute hydrochloric acid. Which of the following is the correct ionic equation for the test for the anion? A Ba2+(aq) + SO4 2-(aq) Æ BaSO4(s) B Ba2+((aq) + 2NO3 -(aq) Æ Ba(NO3)2(s) C Pb2+(aq) + 2Cl-(aq) Æ PbCl2(s) D Ag+(aq) + Cl-(aq) Æ AgCl(s) 13 Which of the following contains 2 aqueous solutions that form green insoluble salts with sodium carbonate solution? Solution 1 Solution 2 A Iron(II) sulfate Zinc sulfate B Lead(II) nitrate Iron(II) nitrate C Iron(II) ethanoate Chromium(III) ethanoate D Aluminium chloride Iron(II) chloride 14 Which of the following solutions when mixed together form a soluble salt? A Aqueous silver nitrate and dilute hydrochloric acid B Aqueous calcium chloride and aqueous silver nitrate C Aqueous lead(II) ethanoate and dilute sulfuric acid D Aqueous potassium hydroxide and dilute nitric acid 15 If 0.0100 mole aqueous sodium chlori de is added to 0.0200 mole aqueous silver nitrate, which of the following ions are present in the solution produced? I Na + III Ag+ II Cl- IV NO3 - A I and IV only C I, III and IV B I, II and IV only D I, II, III and IV

2010 Secondary Three Block Test 2 Nanyang Girls’ High School Setter: LaiSC Chemistry [Turn Over] 5 Section A (15 Marks) Answer the questions (1-15) by filling the answer in the table below. 1 6 11 2 7 12 3 8 13 4 9 14 5 10 15 Section B (20 marks) Answer all questions in this section in the spaces provided B1 Sodium forms 2 compounds with chlorine and oxygen. (a) One mole of NaClO x (one of the compounds) decomposes at room temperature and pressure, accord ing to the equation below to produce 36 dm3 of oxygen. [3] 2NaClOx → 2NaCl + xO2 What is the formula of this compound? (Show all the essential working )

2010 Secondary Three Block Test 2 Nanyang Girls’ High School Setter: LaiSC Chemistry 6 (b) One mole of NaClO y (the other compound) r eacts with 73.0 g of dilute hydrochloric acid to form 58.5 g of sodium chloride, 18 g of water and 24 dm3 of chlorine at room temperature and pressure. (i) Calculate the number of moles of hydrochloric acid reacted and sodium chloride, water and chlorine formed. [1] (ii) Give the chemical equation for the reaction for NaClOy. [1] (iii) Hence give the formula of this compound. [1]

2010 Secondary Three Block Test 2 Nanyang Girls’ High School Setter: LaiSC Chemistry [Turn Over] 7 B2 In an experiment, 2.76 g of sodium react with an exce ss amount of gaseous element E. At the end of the experiment, 12.36 g of compound NaE is obtained. (a) Calculate the mass of gas E reacted with sodium. [1] (b) Determine the relative atomic mass of e