GESS 4Exp Pure Chem Prelim 2024 P1

This document consists of 18 printed pages. GAN ENG SENG SCHOOL Preliminary Examination 2024 CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY Paper 1 Multiple Choice Additional Materials: OTAS 6092/01 9 September 2024 1 hour 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 OTAS. Shade your index number on the OTAS. 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 OTAS 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. Total Marks 40

GESS 4EXP Chemistry 6092/01 PRELIM 2024_JAN 2 1 P, Q, R and S are pieces of apparatus. P Q R S 50 cm3 burette 100 cm3 gas syringe 50 cm3 measuring cylinder 25 cm3 pipette Which row describes the correct apparatus for the measurement made? apparatus measurement made A P the volume of acid added to alkali in a titration B Q 0.24 dm3 of hydrogen gas produced when magnesium reacts with an acid C R 75 cm3 of a gas given off in a rate-determining experiment D S 20 cm3 of alkali for use in a titration 2 X is a mixture of colourless compounds. The diagram shows a chromatogram of X and of three pure compounds, P, Q and R. Which statement is not correct? A X could contain P and R. B Q has a greater Rf value than R. C P and R have different solubilities in the solvent. D A locating agent was used to develop the chromatogram of X.

GESS 4EXP Chemistry 6092/01 PRELIM 2024_JAN 3 3 Which substance can be distilled using the apparatus below? melting point/ oC boiling point/ oC A –138 0 B –123 50 C 0 108 D 41 182 4 Which row about a change of state is correct? change of state energy change process A solid → liquid heat given out melting B gas → liquid heat taken in evaporation C solid → gas heat taken in sublimation D liquid → solid heat given out condensing

GESS 4EXP Chemistry 6092/01 PRELIM 2024_JAN 4 5 The cooling curve for substance X is shown below. At which temperature does both solid and liquid exist? A 0 ºC B 50 ºC C 150 ºC D 200 ºC 6 The ion of an element Z is shown below. In which group and period does element Z belong to in the Periodic Table? group period A 13 2 B 13 3 C 15 2 D 15 3 7 Which row includes an element, a compound and a mixture? A sea water, tap water, pure water B sodium chloride, chlorine, pure water C sea water, sodium chloride, chlorine D sodium chloride, sea water, pure water

GESS 4EXP Chemistry 6092/01 PRELIM 2024_JAN 5 8 Which row correctly classifies how graphite, aluminium and molten sodium chloride conduct electricity? using mobile ions and electrons using mobile electrons only using mobile ions only A molten sodium chloride graphite aluminium B molten sodium chloride aluminium, graphite none of the above C aluminium graphite molten sodium chloride D none of the above aluminium, graphite molten sodium chloride 9 Which dot and cross diagram for a compound of oxygen and chlorine is correct? A B C D 10 Which statement about the structure and properties of silicon(IV) oxide is not correct? A It has a giant covalent structure similar to that of diamond. B There are strong covalent bonds between silicon and oxygen atoms. C Each silicon atom is bonded to four neighbouring oxygen atoms. D It has a high melting point due to the strong attractive force between molecules.

GESS 4EXP Chemistry 6092/01 PRELIM 2024_JAN 6 11 What is the number of molecules in 500 cm3 of oxygen gas at room temperature and pressure? A 1.25 × 1022 B 1.34 × 1022 C 3.0 × 1022 D 3.0 × 1026 12 The percentage by mass of magnesium in chlorophyll-a (Mr = 893) is 2.69%. How many magnesium atoms are there in one molecule of chlorophyll-a? A 1 B 2 C 24 D 100 13 Saline solution is a solution of sodium chloride dissolved in water. It is commonly used in hospitals for cleaning wounds and treating dehydration. A 0.9% saline solution has 0.9 g of sodium chloride for every 100 cm3 of solution. What is the concentration of the 0.9% saline solution in mol/dm3? A 0.00154 mol/dm3 B 0.0154 mol/dm3 C 0.154 mol/dm3 D 1.54 mol/dm3 14 A mixture containing 8.0 g of hydrogen gas with 8.0 g of oxygen gas is ignited. The reaction is represented by the following chemical equation. 2 H2(g) + O2(g) → 2 H2O(l) What is the mass of water formed? A 9.0 g B 16.0 g C 18.0 g D 36.0 g

GESS 4EXP Chemistry 6092/01 PRELIM 2024_JAN 7 15 The diagram shows the results of a pH test on a sample of garden soil. What could be added to the soil to change its pH to 7? A calcium oxide B sodium oxide C sodium chloride D ammonium nitrate 16 The graph shows how pH changes as 0.1 mol/dm3 of dilute sodium hydroxide is gradually added to 0.1 mol/dm3 of ethanoic acid. Which indicator is most suitable to be used in the titration to identify the end-point of neutralisation? indicator colour change pH at which colour change occurs A crystal violet yellow → violet 0.0 – 2.0 B methyl orange red → yellow 3.1 – 4.4 C phenolphthalein colourless → pink 8.3 – 10.0 D indigo carmine blue → yellow 11.4 – 13.0

GESS 4EXP Chemistry 6092/01 PRELIM 2024_JAN 8 17 Copper(II) sulfate is made by reacting excess insoluble solid M and solution N. Which row identifies M and N and the method used to extract crystals of copper(II) sulfate from the mixture? M N method A copper sodium sulfate filter the mixture to obtain the residue B copper sulfuric acid filter the mixture and evaporate filtrate until crystals form C copper(II) oxide sulfuric acid filter the mixture to obtain the residue D copper(II) carbonate sulfuric acid filter the mixture and evaporate filtrate until crystals form 18 Which of the following pairs of gases changes the colour of damp red litmus paper? A ammonia and chlorine B ammonia and carbon dioxide C chlorine and hydrogen D chlorine and sulfur dioxide 19 The diagram shows a reaction scheme. What is Y? A dilute nitric acid B dilute hydrochloric acid C aqueous sodium nitrate D aqueous ammonia

GESS 4EXP Chemistry 6092/01 PRELIM 2024_JAN 9 20 The flowchart below shows the reactions of solution X. solution X add NH3(aq) in excess dirty green precipitate leave to stand red-brown precipitate Which row is correct? formula of dirty green precipitate reaction that resulted in red-brown precipitate A Fe(OH)2 reduction B Fe(NH4)2 reduction C Fe(OH)2 oxidation D Fe(NH4)2 oxidation 21 In which reaction is the underlined substance acting as a reducing agent? A 2 CuO + C → CO2 + 2 Cu B Fe2O3 + 3 CO → 2 Fe + 3 CO2 C 2 Mg + O2 → 2 MgO D MnO2 + 4 HCl → MnCl2 + 2 H2O + Cl2 22 The diagram shows the electrolysis of molten lead(II) bromide. What is seen at each electrode? electrode X electrode Y A brown gas grey metal B colourless gas grey metal C grey metal colourless gas D grey metal brown gas

GESS 4EXP Chemistry 6092/01 PRELIM 2024_JAN 10 23 The diagram shows an experiment to electroplate a nickel spoon with silver. Which row correctly describes the positive electrode, the negative electrode and the electrolyte? positive electrode negative electrode electrolyte A nickel spoon pure nickel silver nitrate solution B nickel spoon pure silver nickel nitrate solution C pure nickel nickel spoon silver nitrate solution D pure silver nickel spoon silver nitrate solution 24 The electrical energy, or voltage, of two simple cells is measured. Which statement correctly describes the results of the expe