2022 WDL Chem Prelims P1

EXPRESS EXPRESS EXPRESS Name: ........................................................................ ( ) Class: ................ WOODLANDS SECONDARY SCHOOL PRELIMINARY EXAMINATION 2022 EXPRESS Level: Secondary Four Express Marks: 40 Subject: Chemistry Day: Wednesday Paper: 6092/01 Date: 24th August 2022 Duration: 1 hour Time: 1235 – 1335 READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name 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. At the end of the examination, submit the OTAS separately from the question paper. A copy of the Periodic Table is printed on page 18. The use of an approved scientific calculator is expected, where appropriate. DO NOT TURN THE PAGE UNTIL YOU ARE TOLD TO DO SO. This document consists of 17 printed pages and 1 blank page. ���

2 6092/PRELIM/P1/2022 EXPRESS EXPRESS EXPRESS 1 Which one of the following apparatus is suitable for measuring 11.60 cm3 of acid? A burette B conical flask C measuring cylinder D pipette 2 Which one of the following correctly describes the particles in a dilute sugar solution at room temperature? sugar molecules water molecules A close together, moving at random widely separated, vibrating slightly B widely separated, moving at random close together, moving at random C widely separated, moving at random close together, not moving D widely separated, not moving widely separated, moving at random 3 The diagram below shows two gas jars separated by a glass lid. The upper gas jar contains brown nitrogen dioxide while the lower gas jar contains colourless hydrogen gas. nitrogen dioxide hydrogen gas glass lid When the glass lid is removed, both gas jars are coloured brown in a short time. What is the reason for this observation? A All molecules are in constant, random motion. B Nitrogen dioxide diffused faster than hydrogen gas. C Nitrogen dioxide is heavier than hydrogen gas. D Nitrogen dioxide reacted with hydrogen gas. ���

3 6092/PRELIM/P1/2022 EXPRESS EXPRESS EXPRESS 4 Which of the following tests is/are best to show that a solution is hydrochloric acid? test action I Add acidified barium nitrate to the solution II Add acidified silver nitrate to the solution III Add sodium carbonate to the solution A I, II and III B II only C II and III only D III only 5 A colourless mixture is separated into its two constituents, P and Q, by paper chromatography as shown below. P and Q are acidic and alkaline in nature respectively. solvent front P 8.0 cm Q 2.8 cm mixture What locating agent should be used, and what is the Rf value of Q? locating agent Rf value of Q A barium nitrate 0.40 B litmus solution 0.35 C methyl orange 0.70 D sodium hydroxide 1.43 ���

4 6092/PRELIM/P1/2022 EXPRESS EXPRESS EXPRESS 6 The diagram below shows the experimental set up for a simple distillation. It is commonly used to separate liquids in a mixture. Which of the following substances may be condensed using a water condenser? substance melting point/ oC boiling point/ oC A ammonia -79 -33 B hydrogen chloride -115 -85 C nitrogen dioxide -73 -10 D pentane -130 36 7 50 cm3 of aqueous bromine was added to 50 cm3 of cyclohexene in a beaker. Two layers of colourless solutions are observed. Which one of the following methods can be used to obtain the organic layer? method organic layer obtained A evaporation bottom layer B evaporation top layer C separating funnel bottom layer D separating funnel top layer ���

5 6092/PRELIM/P1/2022 EXPRESS EXPRESS EXPRESS 8 The graph below shows the temperature changes of a substance as it is heated from room temperature to boiling point. It is a solid at room temperature. Which one of the following conclusion can be made about the substance? A It is a mixture. B It is a liquid between B and C. C Its melting point is 100 oC. D Its boiling point is 110 oC. 9 Which of the following has the same electronic configuration as a calcium ion? A aluminium atom B barium atom C chloride ion D oxide ion 10 Which one of the following correctly gives the numbers of the different sub-atomic particles to be found in a hydroxide ion? protons neutrons electrons A 8 8 8 B 8 8 9 C 9 8 10 D 9 9 10 Temperature / oC Time / min ���

6 6092/PRELIM/P1/2022 EXPRESS EXPRESS EXPRESS 11 X, Y and Z are three elements with consecutive proton (atomic) numbers. X has the lowest proton (atomic) number and Y is a halogen. How can a stable compound be formed? A Each atom of X gives an electron to an atom of Y, to form X+Y-. B Each atom of Y receives an electron from an atom of Z, to form Y-Z +. C Each atom of X shares a pair of electrons with two atoms of Y. D Each atom of X shares an electron with an atom of Y. 12 How many unshared electrons are there in a molecule of ethanoic acid? A 4 B 8 C 12 D 16 13 In which of the following compound(s) is/are covalent bonds found? I aqueous ammonia II graphite III nitric acid A I and II only B I, II and III C II only D II and III only 14 Propane burns completely in oxygen according to the equation shown. C3H8 + 5 O2 ® 3 CO2 + 4 H2O If 100 cm3 of propane is burnt in 200 cm3 of oxygen at 200 oC, what is the total volume of the gases left at the end of the reaction? A 60 cm3 B 180 cm3 C 340 cm3 D 380 cm3 ���

7 6092/PRELIM/P1/2022 EXPRESS EXPRESS EXPRESS 15 What is the concentration of hydrogen ions in 0.5 mol/dm3 sulfuric acid? A 1 g/dm3 B 2 g/dm3 C 49 g/dm3 D 98 g/dm3 16 An aqueous solution has a pH value of 1. What information does this fact give about the ions present in the solution? concentration of H+ ions concentration of OH- ions A high low B high none C low low D low high 17 Which one of the following does not show the correct reaction of nitric acid? reactant product A aqueous ammonia ammonia B barium hydrogen C sodium oxide water D zinc carbonate carbon dioxide 18 Oxides of elements may be classified as acidic, basic or amphoteric. Which set of properties is correctly classified? acidic basic amphoteric A dissolves in water to form acidic solution reacts with acids only reacts with alkalis only B dissolves in water to form acidic solution reacts with acids only reacts with both acids and alkalis C reacts with alkalis only dissolves in water to form alkaline solution reacts wi