2023 DSS Chem Prelims P1

This document consists of 18 printed pages. DUNMAN SECONDARY SCHOOL CANDIDATE NAME CLASS INDEX NUMBER PRELIMINARY EXAMINATION 2023 SECONDARY 4 EXPRESS CHEMISTRY 6092/01 Paper 1 14 September 2023 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, class and index number on the Answer Sheet in the spaces provided unless this has been done for you. 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 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.

2 6092/01/Prelim/4Exp/2023 1 When an excess dilute acid is added to a known quantity of calcium carbonate, the temperature of the mixture changes. A student investigates and measures the temperature changes when calcium carbonate fully reacts with the acid. The student is provided with a beaker and thermometer. Which additional apparatus are needed? 1 mass balance 2 measuring cylinder 3 stopwatch 4 styrofoam cup A 1, 2, 3 and 4 B 1, 2 and 4 only C 1 and 4 only D 2 and 3 only 2 A paper chromatogram is shown in the diagram below. Which statement about the paper chromatogram is correct? 1 A Compound A is heavier than B. B Compound A is more soluble in solvent than B. C The Rf value of compound A, y, is greater than compound B, x. D The solvent level is placed above the starting line. solvent front compound A compound B start line Z Y X

3 6092/01/Prelim/4Exp/2023 3 An organic solvent, hexane and aqueous sodium chloride are accidentally mixed together. Which methods of separation are needed to obtain pure samples of hexane and solid sodium chloride? A filtration followed by crystallisation B fractional distillation followed by evaporation to dryness C simple distillation followed by crystallisation D using a separating funnel followed by evaporation to dryness 4 A gas, R, has the following properties: 1 a choking smell 2 turns damp blue litmus paper red 3 decolourises purple acidified potassium manganate(VII) solution What is R? A ammonia B chlorine C nitrogen D sulfur dioxide 5 Two solutions, W and X, are tested with several reagents, and observations are shown in the table. test observation with W observation with X aqueous ammonia added green precipitate formed, turned brown upon standing white precipitate formed, soluble in excess to form a colourless solution aqueous sodium hydroxide, and aluminium foil added, then wa