2025 CCHY Prelim P1 QP

This document consists of 20 printed pages, INCLUDING the cover page. [Turn over 2025 Preliminary Examination Secondary Four Express CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY 6092/01 Paper 1 Multiple Choice 20 August 2025 Additional Materials: OTAS 1 hour READ THESE INSTRUCTIONS FIRST Write your name, class and index number in the spaces at the top of this page and on the OTAS provided. 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 separate OTAS. Read the instructions on the OTAS 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 20. The use of an approved scientific calculator is expected, where appropriate. O CHUNG CHENG HIGH SCHOOL (YISHUN)

2 CCHY 2025 6092/01/Sec4Express/Prelim/2025 [Turn over 1 A student follows the rate of reaction between marble chips, CaCO 3 and dilute hydrochloric acid. CaCO3 + 2HCl → CaCl2 + CO2 + H2O Which set-ups show the apparatus that are suitable for this experiment? A 1 and 2 only B 1 and 3 only C 2 and 4 only D 1, 2 and 4 only hydrochloric acid marble chips measuring cylinder water hydrochloric acid marble chips balance loose plug hydrochloric acid hydrochloric acid burette burette marble chips marble chips gas syringe

3 CCHY 2025 6092/01/Sec4Express/Prelim/2025 [Turn over 2 A student set s up the apparatus as shown below to collect a sample of clean, dry gas X. Which row correctly gives the identity of gas X and drying agent? gas X drying agent A ammonia calcium oxide B ammonia concentrated sulfuric acid C hydrogen chloride calcium oxide D hydrogen chloride concentrated sulfuric acid 3 Which sequence of procedures is used to separate a pure, dry sample of hydrated copper(II) sulfate, CuSO4.5H2O, from a mixture containing hydrated copper(II) sulfate and calcium carbonate, CaCO3? A dissolve in water → distillation → crystallisation B dissolve in water → filtration → crystallisation C distillation → crystallisation → heating to remove all water D fractional distillation → filtration → heating to remove all water dry sample of gas X mixture of ammonium chloride and calcium hydroxide drying agent

4 CCHY 2025 6092/01/Sec4Express/Prelim/2025 [Turn over 4 A paper chromatography experiment is used to find the R f value for Fe 2+(aq). The chromatogram is shown. To make the spot containing Fe2+(aq) more visible, the paper is sprayed with a locating agent that forms a precipitate of iron(III) hydroxide on the spot. In the chromatogram, the Rf of Fe2+(aq) is given by ……….(1)………. and the colour of the precipitate is ………(2)………. (1) (2) A 0.50 red-brown B 0.50 green C 0.55 red-brown D 0.55 green 5 A liquid is suspected to be pure ethanol. What is the best way to test its purity? A burn it completely in oxygen B measure its boiling point C react with ethanoic acid D test with litmus paper

5 CCHY 2025 6092/01/Sec4Express/Prelim/2025 [Turn over 6 The graph shows the change in the temperature of a substance with time when it is heated from -10oC to 60oC. Which statement describes the change taking place between the points? A Energy is released from points P to Q. B Kinetic energy of the particles remains constant from points P to U. C Particles gain energy to weaken the forces of attraction from points S to T. D There is a large increase in the volume of the substances from points R to S. Temperature/ oC Time/min

6 CCHY 2025 6092/01/Sec4Express/Prelim/2025 [Turn over 7 The number of valence electrons for elements hydrogen to magnesium was plotted against the proton number of the element. Which graph was obtained? proton number proton number proton number proton number number of valence electrons number of valence electrons number of valence electrons number of valence electrons

7 CCHY 2025 6092/01/Sec4Express/Prelim/2025 [Turn over 8 A beam of protons was passed through an electrostatic field between two charged plates. The electrostatic field deflected the beam of protons towards the negatively charged plates. The lower the relative mass of the particle, the larger the deflection. The experiment was repeated using a beam of electrons in place of the beam of protons. Which row correctly shows the extent of deflection and the direction of the beam of electrons? extent of deflection of beam of electrons direction of deflection of beam of electrons A deflected less than beam of protons opposite direction to beam of protons B deflected less than beam of protons same direction as beam of protons C deflected more than beam of protons opposite direction to beam of protons D deflected more than beam of protons same direction as beam of protons 9 An atom of element X is represented by 𝑋4 9 . Which statement about an atom of X is correct? A It is in Group 14 of the Periodic Table. B It is in Period 4 of the Periodic Table. C It forms an ion with a 2+ charge. D The total number of protons and neutrons is 13.

8 CCHY 2025 6092/01/Sec4Express/Prelim/2025 [Turn over 10 Naturally-occurring bromine has a relative atomic mass of 80 and consists entirely of two isotopes of relative atomic masses 79 and 81. What can be deduced about naturally-occurring bromine from this information only? A Bromine contains the two isotopes in equal proportions. B Bromine has different number of electrons. C Bromine isotopes have different number of protons. D Bromine is radioactive. 11 Which substance contains both ionic and covalent bonds? A ammonium chloride B hydrogen chloride C lithium oxide D silicon dioxide 12 A substance Y • has a high melting point; • is a good conductor of electricity; • is malleable. What could Y be? A graphite B iron C potassium chloride D silicon dioxide

9 CCHY 2025 6092/01/Sec4Express/Prelim/2025 [Turn over 13 Some properties of substances P, Q and R are given in the table below. Which row shows the correct classification of the substances as an element, a mixture or a compound? compound element mixture A P Q R B P R Q C Q P R D R P Q 14 0.24 g of an element, X, is reacted with 240 cm3 Cl2 to form a chloride with the formula XCl2 at r.t.p. What is element X? A carbon B calcium C magnesium D titanium substance percentage composition by mass electrical conductivity when solid effect of heat P constant yes solid burns in air to form an oxide Q varies no liquid burns to form carbon dioxide and water R constant no solid decomposes to form two products

10 CCHY 2025 6092/01/Sec4Express/Prelim/2025 [Turn over 15 The manufacture of nitric acid, HNO3, involves 2 steps. Step 1: 2NO + O2 → 2NO2 Step 2: 4NO2 + 2H2O + O2 → 4HNO3 What is the maximum number of moles of nitric acid that could be formed from 0.50 moles of nitrogen monoxide, NO? A 0.125 B 0.25 C 0.50 D 1.00 16 Which hydrocarbon has the highest percentage of hydrogen by mass? A CH4 B C3H8 C C4H10 D C5H12 17 On heating, ammonium nitrate, NH 4NO3, decomposes to form dinitrogen oxide and water. NH4NO3 → N2O