TKGS 2026 Chem Prelim P1 QP

1 TANJONG KATONG GIRLS’ SCHOOL PRELIMINARY EXAMINATION SECONDARY FOUR EXPRESS CHEMISTRY CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY 6092/01 Paper 1 Multiple Choice 24 August 2026 1 hour Additional Materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Write your name, index number on the Answer Sheet. 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 23. The use of an approved scientific calculator is expected, where appropriate. This document consists of 22 printed pages and 1 blank page.

Tanjong Katong Girls’ School 3 Sec 4 Preliminary Examination 2026 1 A gas dissolves readily in water, turns moist blue litmus paper red, and is denser than air. Which set up should be used to dry and collect this gas? 2 A student accidentally mixed 50 cm3 of oil and 5 g of solid calcium nitrate. Which sequence of separation would allow him to obtain pure samples of oil and solid calcium nitrate most easily? A Carry out simple distillation followed by crystallisation. B Carry out filtration followed by washing the residue with water. C Use a separating funnel, carry out chromatography followed by crystallisation. D Add water with stirring, use a separating funnel followed by crystallisation.

Tanjong Katong Girls’ School 4 Sec 4 Preliminary Examination 2026 3 Chromatography was carried out on a urine sample using two different solvents. Based on the two chromatograms, which drug(s) is/are present in the urine sample? A drug P only B drug Q only C drugs P and Q only D drugs P, Q and R 4 The electronic structure of an ion is shown: What is the number of protons in this ion? A 9 B 10 C 11 D It cannot be deduced from this diagram. chloroform solvent used propanol solvent used sample drug P drug Q drug R sample drug P drug Q drug R

Tanjong Katong Girls’ School 5 Sec 4 Preliminary Examination 2026 5 Which diagrams show the physical states of iodine before and after sublimation? before after A B C D 6 Four elements W, X, Y, and Z have consecutive, increasing proton (atomic) numbers. Element Y exists as a colourless, monatomic gas at room temperature. What is the chemical formula of a compound formed between W and chlorine? A WCl B W2Cl C WCl2 D W2Cl3

Tanjong Katong Girls’ School 6 Sec 4 Preliminary Examination 2026 7 Ammonium chloride is heated strongly in a boiling tube. Damp blue and red litmus papers were placed at the mouth of the boiling tube. NH4Cl ⇌ NH3 + HCl Which row shows the correct sequence of observations that would be made? first observed colour change final colour of both litmus papers A The damp blue litmus paper turns red red B The damp blue litmus paper turns red then bleaches white C The damp red litmus paper turns blue blue D The damp red litmus paper turns blue red damp blue litmus paper damp red litmus paper ammonium chloride heat

Tanjong Katong Girls’ School 7 Sec 4 Preliminary Examination 2026 8 The atomic structure of an element is shown. Which diagram shows the atomic structure of an isotope of this element?

Tanjong Katong Girls’ School 8 Sec 4 Preliminary Examination 2026 9 Since the discovery of graphite, scientists have been able to extract a single layer of carbon atoms (known as graphene) and convert it to another material known as graphane, by attaching one hydrogen atom to each carbon atom as shown below. Which property of graphene is not likely to be shared by graphane? A It is insoluble in water. B It is very strong. C It has a high melting point. D It is an electrical conductor. 10 0.1 mole of XCl2 combines with 10.8 g of water to form a hydrated salt, XCl2.nH2O. What is the value of n? A 6 B 8 C 10 D 12 11 Hydrogen reacts with chlorine to form hydrogen chloride. H2(g) + Cl2(g) → 2HCl(g) What is the final volume of the gas mixture when 20 dm 3 of hydrogen is reacted with 30 dm3 of chlorine? A 40 dm3 B 50 dm3 C 60 dm3 D 70 dm3

Tanjong Katong Girls’ School 9 Sec 4 Preliminary Examination 2026 12 When 4.8 g of magnesium is heated in a crucible, 5.9 g of magnesium oxide is formed. 2 Mg + O2 → 2 MgO What is the percentage yield of magnesium oxide? A 53% B 74% C 80% D 81% 13 P, Q and R are elements found in Group 17 of the Periodic Table. Three reactions are carried out to determine the reactivity of P, Q and R. 1 P2 (aq) + 2R- (aq) → R2 (aq) + 2P- (aq) 2 Q2 (aq) + 2P- (aq) → no reaction 3 Q2 (aq) + 2R- (aq) → R2 (aq) + 2Q- (aq) Which statement about P, Q and R is correct? A P has a darker colour than R. B Q is a stronger oxidising agent than R. C Q is more reactive than P. D R is a gas at room temperature and pressure. 14 Strontium lies below calcium and magnesium in Group 2 of the Periodic Table. Which property could be predicted for strontium? A It forms a covalent compound with chlorine. B It is displaced from its nitrate solution by magnesium. C It is extracted from its ore by heating with carbon. D It reacts readily with cold water to form an alkali.

Tanjong Katong Girls’ School 10 Sec 4 Preliminary Examination 2026 15 X, Y and Z are in the same period of the Periodic Table. • The oxide of X reacts with water to form a solution with pH less than 7. • The oxide of Y reacts with water to form a solution that turns damp red litmus paper blue. • The oxide of Z is soluble in both dilute hydrochloric acid and aqueous sodium hydroxide. What is the order of increasing proton number for elements X, Y and Z? A X, Y, Z B X, Z, Y C Y, Z, X D Z, Y, X 16 Which of the following statements regarding caesium are correct? 1 It reacts with water to form a metal oxide and hydrogen gas. 2 It reacts with dilute acid to release more heat than potassium. 3 It has a lower density than sodium. 4 It has a lower melting point than lithium. A 1 and 2 B 2 and 4 C 1, 2 and 3 D 2, 3 and 4

Tanjong Katong Girls’ School 11 Sec 4 Preliminary Examination 2026 17 Which element in the table is most likely to be a transition metal? melting point (0C) density (g/cm3) number of chlorides formed A -7 3.10 3 B 113 2.07 1 C 1083 8.92 2 D 1521 1.12 1 18 Substance L was added slowly until in excess, with stirring, to aqueous solution J. The changes in pH of the mixture are shown in the graph. What c