ADSS Prelim P1

This question paper consists of 19 printed pages including this cover page. ADMIRALTY SECONDARY SCHOOL SUBJECT : Chemistry CODE/PAPER : 6092/1 LEVEL/STREAM : Secondary 4 Express DATE : 26 August 2024 TIME : 0800h – 0900h DURATION : 1 hour READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, class and register number on the Optical Answer Sheet provided unless this has been done for you. There are forty questions on 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 Optical Answer Sheet. Fill in the Optical Answer Sheet very carefully. 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 question paper. A copy of the Periodic Table is printed on page 19. The use of an approved scientific calculator is expected, where appropriate. DO NOT TURN OVER THIS PAPER UNTIL YOU ARE TOLD TO DO SO. PRELIMINARY EXAMINATION 2024 NAME: NO: CLASS: 40

2 1 A student sets up the apparatus as shown below. What gas will be collected from the set-up shown and what would be a suitable dehydrating agent? name of gas dehydrating agent A ammonia gas concentrated sulfuric acid B ammonia gas calcium oxide C hydrogen chloride concentrated sulfuric acid D hydrogen chloride calcium oxide 2 A bottle of magnesium carbonate has been contaminated with sodium chloride. How can pure magnesium carbonate be obtained from this mixture? A Add acid to the mixture, filter then evaporate the filtrate. B Add acid to the mixture, filter then collect the residue. C Add water to the mixture, filter then evaporate the filtrate. D Add water to the mixture, filter then collect the residue. 3 Which piece of apparatus could be used to determine the end-point of the reaction between hydrochloric acid and potassium hydroxide? A electronic balance B gas syringe C stopwatch D thermometer

3 4 Which of the following best describes the particles present in a diluted solution of potassium chloride? potassium chloride ions water molecules A far apart close together B close together close together C close together far apart D far apart far apart 5 In a porous pot experiment, the porous pot was placed in a beaker of nitrogen. The porous pot was joined to a U tube filled with mercury as shown. Which of the gases, 1 to 4, when used to fill the porous pot would cause level A to move down? 1 ammonia 2 carbon dioxide 3 chlorine 4 hydrogen A 1 and 3 only B 1 and 4 only C 2 and 3 only D 2 and 4 only level A nitrogen mercury U-tube porous pot

4 Diagram A Diagram B −90oC −5oC 6 The diagrams show the particles in a substance at two different temperatures but at the same pressure. Which of the following most likely indicates the melting point and boiling point of the substance? melting point / oC boiling point / oC A −70 30 B −70 −10 C −100 −70 D −120 −10 7 The graph shows the change in temperature with time when a substance at 120 °C is cooled to −20 °C. Which statement correctly describes the change taking place between the points? A The volume of vapour is decreasing from R to S. B The particles release energy as they become closer together from Q to R. C The particles absorb energy as they become more orderly from S toT. D The energy of the particles remains constant from S to T. 8 Which ion has the least number of occupied shells? A Ca 2+ B N3− C Li+ D Cl− Diagram A Diagram B

5 9 Deuterium, D, is an isotope of hydrogen. Which of the following statements about deuterium is not correct? A It reacts with ethene, C2H4 to form a compound CH2DCH2D. B An atom of deuterium contains one proton. C It has the same density as hydrogen. D It forms the ion D+. 10 The diagrams below show the structures of the atoms of two elements. What is the relative molecular mass of the compound formed by these two elements? A 11 B 14 C 23 D 30 11 The diagram below shows a simplified structure for asbestos. What is/are the bonding(s) in asbestos? A covalent only B ionic only C covalent and ionic D ionic and metallic

6 12 The outer shell electrons in compound YZ2 are shown. Atom Y is in Period 2 of the Periodic Table. What is the number of protons in atom Y? A 6 B 8 C 10 D 12 13 Silicon carbide has a similar structure to diamond. Which one of the following are advantages of using a silicon carbide ceramic compound instead of steel in manufacturing industry? 1 Silicon carbide has a higher melting point. 2 Silicon carbide is more resistant to oxidation. 3 Silicon carbide is less likely to deform under compression. A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3 14 Element R has the following properties.  forms RBr2 when reacted with liquid bromine  forms R(NO3)3 when reacted with dilute nitric acid Which of the following best describes element R? A group 2 element B group 17 element C group 18 element D transition element Y Z Z

7 15 Which ionic equation represents the reaction when aqueous barium nitrate is added to sulfuric acid? A 2H+ (aq) + SO42- (aq)  H2SO4 (aq) B Ba2+ (aq) + SO42- (aq)  BaSO4 (s) C 2H+ (aq) + Ba2+ (aq)  H2 (g) + Ba (s) D H+ (aq) + NO3 - (aq)  HNO3 (aq) 16 1.97 g of an unknown metal carbonate, MCO3, reacts completely with 50.0 cm3 of 0.400 mol/dm3 hydrochloric acid. What is the relative atomic mass of M? A 35.0 B 94.5 C 137 D 150 17 It was found that 20.0 cm3 of 0.500 mol/dm3 dilute hydrochloric acid completely reacted with 0.70 g of a sample of sodium carbonate contaminated with sodium chloride. What is the percentage purity of the sodium carbonate in the sample. A 44.5% B 45.4% C 75.7% D 80.9% 18 Dinitrogen tetroxide, N2O4, is a poisonous gas. It can be disposed of safely by reacting with sodium hydroxide, NaOH. N2O4(g) + 2NaOH(aq)  NaNO3(aq) + NaNO2(aq) + H2O(l) What is the least mass of sodium hydroxide required to dispose of 300 cm3 of N2O4 at room temperature and pressure? A 1.0 g B 2.0 g C 10.0 g D 20.0 g

8 19 Solution X and solid Y are mixed in a beaker. After mixing, the final mass of the substances and the beaker is lesser than the initial mass. What could solution X and solid Y be? solution X solid Y A hydrochloric acid iron(III) hydroxide B nitric acid magnesium oxide C potassium hydroxide ammonium carbonate D sulfuric acid copper 20 A dilute aqueous solution of a strong alkali, XOH, contains molecules of water and the ions X+ and OH. Which statement is correct? A The solution also contains H+ ions. B The pH value of the alkali is below 7. C The solution contains more OH ions than water molecules. D The solution contains a high concentration of XOH molecules.

9 21 Different indicators change colour over different pH ranges and it is important to choose the correct indicator to obtain an accurate result in a titration. indicator pH range for the colour change indigo carmaine 11.6 to 14.0 methyl red 4.2 to 6.3 methyl violet 0.3 to 3.0 phenolphthalein 8.2 to 10.0 Which of the indicators would be the best choice to use in the titration above? A indigo carmaine B methyl red C methyl violet D phenolphthalein