BLSS Prelim P1 ans

2 BLS/PRELIM/2024/4E/CHEMISTRY/6092/01 4E Chemistry Preliminary Examination 2024 Paper 1 Answers 1 2 3 4 5 6 7 8 9 10 B B A A D A C C B B 11 12 13 14 15 16 17 18 19 20 A C B D D A A B D D 21 22 23 24 25 26 27 28 29 30 C D A A A D A D A A 31 32 33 34 35 36 37 38 39 40 C B D C D B C D C A

3 BLS/PRELIM/2024/4E/CHEMISTRY/6092/01 1 The graph shows the change in temperature with time when ice at –20 oC is heated to 120 oC. Which row shows the correct change taking place between the points? points change A P to Q average energy of particles remain constant B Q to R ice melting C R to S the volume of steam is increasing D T to U water boiling 2 The apparatus can be used to show the diffusion of gases. Which pair of gases X and Y would cause no movement of the coloured water? X Y A C2H4 C2H6 B C2H4 N 2 C CO2 C2H6 D CO NO 2 3 Which apparatus is most suitable to measure 27.8 cm3 of a solution? A burette B beaker C pipette D measuring cylinder temperature / oC time porous pot beaker coloured water gas X

4 BLS/PRELIM/2024/4E/CHEMISTRY/6092/01 4 Which mixture can be separated into its components by adding water, stirring and filtering? A calcium carbonate and sodium chloride B magnesium and iron C sodium chloride and copper(II) sulfate D sulfuric acid and hydrochloric acid 5 Which ion has the most number of shells that contain electrons? A Al3+ B Be2+ C N3– D S2– 6 The relative atomic mass of naturally occurring chlorine is not a whole number. What is the reason for this? A Chlorine atoms can have different numbers of neutrons. B Chlorine is unstable. C Naturally occurring chlorine cannot be obtained pure. D The mass of the electrons has been included. 7 Which statement explains why potassium chloride, KCl, has a lower melting point than calcium oxide, CaO? A Potassium chloride is covalent but calcium oxide is ionic. B Potassium is more reactive than calcium. C The attraction between the potassium ions and chloride ions is weaker than that between the calcium ions and oxide ions. D The melting point of potassium is lower than that of calcium. 8 The diagram shows the structure of a compound of carbon and silicon, (SiC)n. What will be a property of (SiC)n? A acts as a lubricant B conducts electricity C insoluble in water D low melting point 9 The element R has three electrons in its outer shell. What is the formula of the oxide of element R? A RO3 B R2O3 C R2O5 D R3O2

5 BLS/PRELIM/2024/4E/CHEMISTRY/6092/01 10 Over 71 000 kg of oil-soaked sand was scooped up from the three Sentosa beaches, one day after tonnes of fuel leaked into the sea from an oil spill. The contaminated sand was sent to an industrial wast