AMKSS Prelim P3 2025 with ans

[Turn over Name Class Index Number SCIENCE (CHEMISTRY) Paper 3 Multiple Choice 5105/03 5 August 2025 Setter: Ms Audrey Ferng Papers 3 and 4: 1 hour 15 minutes Additional Materials: OTAS Paper READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, class and index number in the spaces at the top of this paper and the OTAS. There are twenty 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 separate OTAS. Read the instructions on the OTAS very carefully. Answers to Paper 3 and Paper 4 must be handed in separately. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. You are advised to spend no more than 30 minutes on Paper 3. You may proceed to answer Paper 4 as soon as you have completed Paper 3. Any rough working should be done in this booklet. A copy of the Periodic Table is printed on page 9. The use of an approved scientific calculator is expected, where appropriate. This document consists of 9 printed pages and 1 blank page. . ANG MO KIO SECONDARY SCHOOL PRELIMINARY EXAMINATION 2025 SECONDARY FOUR NORMAL ACADEMIC

2 AMKSS Prelim 2025 5105/03/2025 [Turn over 1 The diagram below shows the volume of nitrogen gas collected in a gas syringe. What is the reading shown? A 66.0 cm3 B 70.5 cm3 C 72.0 cm3 D 84.0 cm3 2 A lab analyst carried out paper chromatography to investigate the presence of banned performance- enhancing drug substances P, Q, R and S in the urine sample of athlete M1. The paper chromatogram of the results is shown below. Which of the following drugs P, Q, R and S did the athlete M1 consume? A P and Q B Q and R C Q and S D R and S nitrogen gas M1 P Q R S

3 AMKSS Prelim 2025 5105/03/2025 [Turn over 3 Some sodium chloride salt has been mixed with sand. What is the correct order to purify the salt using water as a solvent? A dissolving → filtering → distillation B dissolving → filtering → evaporating C filtering → evaporating → dissolving D filtering → dissolving → evaporating 4 The following table shows the boiling points of the elements found in a sample of liquid air. element boiling point /°C argon -186 helium -269 neon -246 nitrogen -196 oxygen -183 Which elements would be gaseous at –190°C? A argon, helium and nitrogen B argon, nitrogen and oxygen C helium, neon and nitrogen D helium, neon and oxygen 5 The diagram below represents a particle. What is the identity of the particle? A F− ion B K+ ion C Na+ ion D Ne atom

4 AMKSS Prelim 2025 5105/03/2025 [Turn over 6 Which two elements combine to form an ionic compound? A beryllium and sodium B carbon and nitrogen C potassium and chlorine D silicon and oxygen 7 The diagram shows the electron arrangement in a molecule of compound YZ3. Identify elements Y and Z. Y Z A aluminium chlorine B nitrogen fluorine C phosphorus hydrogen D sulfur nitrogen 8 Which of the following shows the electrical conductivities of an ionic compound in different physical states? electrical conductivity in solid state electrical conductivity in molten state electrical conductivity in aqueous state A good good good B poor good good C poor poor good D good good poor Y Z Z Z

5 AMKSS Prelim 2025 5105/03/2025 [Turn over 9 The following chemical equation shows the burning of propane in an excess of air. C3H8 + x O2 → y CO2 + z H2O What values of x, y and z would balance the equation? x y z A 3 5 5 B 4 4 5 C 5 3 3 D 5 3 4 10 A compound has the chemical formula Fe(OH)x. The relative molecular mass of the compound is 107. What is the value of x? A 1 B 2 C 3 D 4 11 The apparatus was set up as shown. When the test tube was heated, the litmus paper turned blue. What could solid S be? A aluminium B ammonium sulfate C copper(II) sulfate D hydrochloric acid

6 AMKSS Prelim 2025 5105/03/2025 [Turn over 12 Which substance cannot react with either hydrochloric acid or sodium hydroxide? A carbon monoxide B magnesium oxide C sulfur dioxide D zinc oxide 13 The graph shows the pH of a sample of soil as lime (calcium oxide) is added. How much lime is added to make the same sample of soil neutral? A 1.5 g B 2.0 g C 3.0 g D 4.0 g 14 The diagram shows some elements in Period 3 of the Periodic Table. Which statement is not true? 11 Na sodium 23 12 Mg magnesium 24 13 Al aluminium 27 14 Si silicon 28 15 P phosphorus 31 16 S sulfur 32 17 Cl chlorine 35.5 18 Ar argon 40 A Aluminium atom a relative mass of 13. B Sodium atom has 12 neutrons. C The electrons of each atom of silicon occupy three electron shells. D The phosphorus atoms gain electrons to form negative ions. mass of lime / g pH 0 1.0 2.0 3.0 4.0 14 12 10 8 6 4 2 0

7 AMKSS Prelim 2025 5105/03/2025 [Turn over 15 Caesium, Cs, is an element in Group 1 of the Periodic Table. Which statements about Caesium are true? 1 Caesium conducts electricity both when solid and when molten. 2 Caesium reacts explosively with water. 3 Caesium reacts with water and forms a solution of pH less than 7. A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3 16 Which of the following shows the correct method used in the extraction of the metal from its ore? metal method of extraction A copper electrolysis B iron reduction using carbon C lead electrolysis D potassium reduction using carbon 17 Which hydrocarbon is a member of the alkane series? A C5H10 B C6H6 C C8H18 D C10H20 18 Methane and chlorine react together in the presence of sunlight. Which chemical equation represents the reaction that takes place? A CH4 + 2Cl → CH3Cl + HCl B CH4 + Cl2 → CH3Cl + HCl C CH4 + 2Cl → CH4Cl2 D CH4 + Cl2 → CH4Cl2

8 AMKSS Prelim 2025 5105/03/2025 [Turn over 19 The diagram shows part of the structure of a polymer. Which monomer is used to manufacture the polymer? A B C D 20 Which statements about the pollutant carbon monoxide are correct? 1 It reacts with haemoglobin in the blood. 2 It is a colourless, odourless gas. 3 It is formed by incomplete combustion of fossil fuels. A 1 and 2 only B 1 and 3 only C 2 and 3