YCKSS Prelim P1

Name: Index Number: Class: YIO CHU KANG SECONDARY SCHOOL O-LEVEL PRELIMINARY EXAMINATION 2024 SECONDARY FOUR EXPRESS CHEMISTRY 6092/01 Paper 1 1 hour 23 August 2024 (Friday) Additional Materials: Optical Answer Sheet (OAS) READ THESE INSTRUCTIONS FIRST Write in soft pencil on the OAS. Do not use staples, paper clips, glue or correction fluid. Write your name, index number and class on the OAS in the spaces 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 OAS. Read the instructions on the OAS 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. The use of an approved scientific calculator is expected, where appropriate. A copy of the Periodic Table is printed on page 20. For Examiner’s Use 40 Setter: Mdm Connie Yeo This document consists of 18 printed pages and 2 blank pages.

2 4E PRELIM EXAM 2024 6092/01 1 At which temperature does a dilute solution of sodium chloride begin to boil? A 90oC B 98oC C 100oC D 102oC 2 Samples of pure and impure aspirin were analysed using chromatography. The resulting chromatogram is shown below. The impure sample of aspirin was contaminated with one of the raw chemicals used during production. What is the Rf value of the chemical? A 0.24 B 0.37 C 0.68 D 0.73 solvent front start line 2.2 cm 4.4 cm 6.0 cm Key X = impure aspirin Y = pure aspirin 1.0 cm 0.0 cm

3 4E PRELIM EXAM 2024 6092/01 3 Four mixtures, each containing two substances, are shown in the table. The two substances need to be separated and collected. Which row is correct? mixture separation method A ethanol and methanol evaporation B ink and water chromatography C oxygen and nitrogen fractional distillation D sand and calcium sulfate filtration 4 In which changes do the particles move further apart? 1 A gas is heated from 0oC to 25oC. 2 Iodine vapour coming into contact with cold surface. 3 Pressure is applied to a gas at a constant temperature. 4 Water boiling to form steam. A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4 5 The table gives data about four substances. Which substance has particles in an orderly arrangement at room temperature? melting point/oC boiling point/oC A –101 –34 B -39 357 C -7 59 D 113 445

4 4E PRELIM EXAM 2024 6092/01 6 A gas Z, is less dense than air, very soluble in water and is alkaline. Which method is used to collect a dry sample of the gas? A B C D 7 Gases can diffuse through porous pots. The diagram shows a beaker full of nitrogen inverted over a porous pot containing carbon monoxide. The water level does not move. Which statement explains this? A Both gases are insoluble in water. B Both gases are neutral. C Both gases have the same molecular masses. D Both gases have two atoms in a molecule. Z dry Z dry Z dry Z dry Z Z Z Z water fused calcium chloride concentrated sulfuric acid calcium oxide water nitrogen beaker porous pot carbon monoxide

5 4E PRELIM EXAM 2024 6092/01 8 Substances can be elements, compounds or mixtures. Which row is correct? element compound mixture A carbon glucose petroleum B nitrogen brass air C oxygen carbon dioxide methane D zinc steel seawater 9 The symbols and represent atoms of different elements. Which diagram shows a mixture of elements? A B C D 10 Two particles K and L have the composition shown in the table. particle number of electrons number of neutrons number of protons K L 10 18 12 20 11 20 What are particles K and L? A metal atoms B non-metal atoms C negative ions D positive ions

6 4E PRELIM EXAM 2024 6092/01 11 Two particles have the symbols 𝐹𝑒ଶ଺ହ଼ 2+ and 𝐶𝑜ଶ଻ହ଼ 3+. Which statement about these particles is/are correct? 1 They contain the same number of electrons. 2 They contain the same number of neutrons. 3 They have different number of protons, neutrons or electrons. 4 They have the same mass number. A 1 and 2 only B 1 and 4 only C 2 and 4 only D 3 only 12 The octet rule may or may not be obeyed by the atoms in the chlorite ion, ClO2-. Which is the correct structure of the chlorite ion? A B C D 13 The relative molecular mass of liquid P is 60. P contains 40.0% carbon, 6.70% hydrogen and 53.3% oxygen. Which row shows the correct empirical and molecular formulae of P? empirical formula molecular formula A CH2O CH 2O B CH2O C 2H4O2 C CH3O C 2H6O2 D C2H4O2 C 2H4O2

7 4E PRELIM EXAM 2024 6092/01 14 Hydrogen sulfide reacts with sulfur dioxide to produce sulfur. H2S (aq)  S (s) + 2H+ (aq) + 2e- SO2 (aq) + 4H+ (aq) + 4e-  S (s) + 2H2O (l) How many moles of hydrogen sulfide are needed to produce one mole of sulfur? A ଵ ଷ mol B ଶ ଷ mol C ଷ ଶ mol D 2 mol 15 A student made calcium chloride by reacting 15.0 g of calcium carbonate with hydrochloric acid. The equation for the reaction is CaCO3 + 2HCl  CaCl2 + CO2 + H2O The percentage yield of calcium chloride was 85%. Calculate the mass of calcium chloride the student actually produced. A 13.8 g B 14.2 g C 16.2 g D 16.7 g 16 Elements X and Y combine to form a covalent compound. Atoms of X have more protons than atoms of Y. Atoms of Y have more valence electrons than atoms of X. Which statement is correct? A Atoms of X have more electron shells than atoms of Y. B Ions of X are positively charged. C X and Y are in the same period of the Periodic Table. D X and Y are in the same group of the Periodic Table.

8 4E PRELIM EXAM 2024 6092/01 17 The elements in Group 1 of the Periodic Table show trends in both their reactivities and their melting points. Rubidium is in Group 1. Which statement about rubidium is correct? A It has a higher melting point than potassium. B It is more reactive than potassium. C It reacts with water to produce an acidic solution. D It reacts with water to produce oxygen gas. 18 A solution of potassium halide and a halogen are