2025 TKGS Chemistry Prelim Paper 1 QP

Tanjong Katong Girls’ School 1 Sec 4 Preliminary Examination 2025 1 TANJONG KATONG GIRLS’ SCHOOL PRELIMINARY EXAMINATION SECONDARY FOUR EXPRESS CHEMISTRY CANDIDATE NAME CLASS 4 INDEX NUMBER CHEMISTRY 6092/01 Paper 1 Multiple Choice 22 August 2025 1 hour Additional Materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, Centre number and index number on the Answer Sheet in the spaces provided unless this has been done for you. Do NOT WRITE on ANY BARCODES. There are forty questions in 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 Answer Sheet. Read the instructions on the 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 booklet. A copy of the Periodic Table is printed on page 18. The use of an approved scientific calculator is expected, where appropriate. This document consists of 18 printed pages.

Tanjong Katong Girls’ School Sec 4 Preliminary Examination 2025 2 1 Sulfur dioxide gas can be prepared by heating sodium sulfite with hydrochloric acid. Which set of apparatus is suitable for preparing and collecting a dry sample of sulfur dioxide? 2 A student wants to separate a mixture of iodine and sodium chloride. Which method should she use? A Crystallisation B Sublimation C Filtration D Distillation

Tanjong Katong Girls’ School Sec 4 Preliminary Examination 2025 3 3 X, Y and Z are all mixture of alcohols. A paper chromatogram is obtained for samples of X, Y and Z. Which row is correct? statement 1 statement 2 A Z contains no more than four alcohols X, Y and Z could contain the same alcohol B Z contains no more than four alcohols X, Y and Z could not contain the same alcohol C Z contains at least four alcohols X, Y and Z could contain the same alcohol D Z contains at least four alcohols X, Y and Z could not contain the same alcohol 4 What happens as ice melts at 0ºC? 1 Molecules gain kinetic energy and temperature increases. 2 Energy is gained to overcome the intermolecular forces of attraction. 3 Molecules gain sufficient energy to move from fixed positions. A 1 only B 1 and 2 only C 1 and 3 only D 2 and 3 only

Tanjong Katong Girls’ School Sec 4 Preliminary Examination 2025 4 5 Which gas diffuses most rapidly under the same conditions of temperature and pressure? A Cl2 B CO2 C CH4 D NO2 6 Which statement about electrons, neutrons and protons is correct? A The relative charge of a proton is equal but opposite in sign to the relative charge of an electron. B The relative charge of a proton is the same as the relative charge of a neutron. C The relative mass of an electron is about 2000 times the relative mass of a neutron. D The relative masses of protons and electrons are the same. 7 Which statement about isotopes is correct? A They have different numbers of electrons and react differently in chemical reactions. B They have the same number of neutrons and exhibit identical chemical and physical properties. C They have different mass numbers b ut undergo the same chemical reactions. D They have different proton numbers and belong to different elements.

Tanjong Katong Girls’ School Sec 4 Preliminary Examination 2025 5 8 The table shows the number of subatomic particles in different atoms or ions. number of neutrons number of protons number of electrons W 12 12 10 X 13 12 12 Y 16 15 18 Z 18 17 18 Which statements about W, X, Y and Z are correct? 1 W has a charge of 2–. 2 W and Y form W2Y3. 3 WZ2 has a giant ionic structure. A 1 and 2 only B 1 and 3 only C 2 and 3 only D 3 only 9 Which structure corresponds to its description of physical properties? structure physical properties 1 giant covalent high melting point, conducts electricity when in solution but not when solid 2 simple molecular low melting point, does not conduct electricity in any state 3 giant metallic variety of melting points, conducts electricity when solid and when molten A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

Tanjong Katong Girls’ School Sec 4 Preliminary Examination 2025 6 10 Nitric acid reacts with a wide range of elements and compounds. P4 + aHNO3 → 4H3PO4 + 4H2O + 20NO2 What is the value of a in the correctly balanced equation? A 5 B 10 C 15 D 20 11 Which two pieces of information are most essential to calculate the relative molecular mass of a compound? A the empirical formula and the relative atomic masses of the elements in the compound B the empirical formula and the total number of atoms of each element in the compound C the molecular formula and the percentage by mass of each element in the compound D the molecular formula and the relative atomic masses of the elements in the compound 12 Copper, in the form of CuFeS2, is extracted from ores in copper mines. The ore contains only 1% by mass of copper. What percentage of the ore contains CuFeS2, if it is the only copper-containing compound present? A 1.00% B 2.88% C 3.47% D 34.70% 13 Boron carbide contains boron and carbon. A sample contains 0.78 g of boron and 0.22 g of carbon. What is the empirical formula of boron carbide? A BC2 B BC4 C B2C D B4C

Tanjong Katong Girls’ School Sec 4 Preliminary Examination 2025 7 14 An element forms a diatomic molecule, Q, which has a relative molecular mass, x. The Avogadro constant is L. How many atoms are present in 1.0 g of Q? A L x B 2L x C L 2x D 2LX 15 A farmer tests the soil and finds it has a pH of 4.5. Which substance should she add to correct the pH? A ammonium sulfate B calcium hydroxide C sulfur dioxide D potassium nitrate 16 Which oxides react with aqueous sodium hydroxide? 1 copper(II) oxide 2 carbon dioxide 3 zinc oxide A 2 only B 3 only C 1 and 3 only D 2 and 3 only 17 A salt can be prepared by adding an excess of solid X to an aqueous solution of Y. A solution and some solid X remain. The mixture is filtered. The filtrate is evaporated to form a concentrated solution, which is left to crystallise. Excess solution is poured off, leaving salt Z. Which salt can be safely prepared using this method? A ammonium chloride B copper(II) sulfate C barium sulfate D potassium chloride

Tanjong Katong Girls’ School Sec 4 Preliminary Examination 2025 8 18 Which statement about the Haber process for the manufacture of ammonia is correct? A At higher temperatures, the yield increases and the rate of production of ammonia is faster. B At higher pressure, the yield increases and the rate of production of ammonia is faster. C In the presence of a catalyst, the yield decreases but the rate of production of ammonia is faster. D In the presence of a catalyst, the yield increases and the rate of production of ammonia is faster. 19 Filings of an alloy containing zinc and aluminium reacted with dilute hydrochloric acid to form a solution. Excess aqueous ammonia was added to the solution with shaki