2022 SSS Chem Prelims P1

1 SERANGOON SECONDARY SCHOOL PRELIMINARY EXAMINATION SECONDARY 4 EXPRESS CANDIDATE NAME ( ) CLASS CENTRE NUMBER S INDEX NUMBER CHEMISTRY 6092/01 Paper 1 Multiple Choice 24 Aug 2022 1 hour Additional Materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, 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 the last page. The use of an approved scientific calculator is expected, where appropriate. This question paper consists of 19 printed pages, including this cover page. For examiner’s use 40 ���

2 1 25 cm3 of aqueous sodium hydroxide is pipetted into a conical flask and titrated with dilute hydrochloric acid from a burette. How can the accuracy of the titration be improved? I. Rinse the interior of the pipette with aqueous sodium hydroxide. II. Rinse the interior of the pipette with aqueous hydrochloric acid. III. Rinse the interior of the conical flask with aqueous sodium hydroxide. IV. Rinse the interior of the burette with dilute hydrochloric acid. A I and III only B I and IV only C II and III only D I, III and IV 2 The diagram below is a set-up used to obtain carbon monoxide. What is the main purpose of the aqueous sodium hydroxide? A Dry the carbon monoxide. B Remove the carbon dioxide. C Remove the excess acid. D Remove the oxygen present. water aqueous sodium hydroxide carbon monoxide calcium carbonate lumps of charcoal heat dilute hydrochloric acid ���

3 3 Esters can be prepared by reactions of alcohols and carboxylic acids. The yield of these reactions is often low. One way of improving the yield is to remove the ester formed as the reaction proceeds and this can be done by carrying out fractional distillation. Which of the following mixtures will yield an ester as the distillate using this method? A ethanol (B.P: 78oC) ethanoic acid (B.P: 118oC) ethyl ethanoate (B.P: 77oC) B butanol (B.P: 117oC) ethanoic acid (B.P: 118oC) butyl ethanoate (B.P: 128oC) C ethanol (B.P: 78oC) butanoic acid (B.P: 164oC) ethyl butanoate (B.P: 121oC) D methanol (B.P: 65oC) butanoic acid (B.P: 164oC) methyl butanoate (B.P: 102oC) 4 Vitamins are essential nutrients needed in small amounts for various roles in the human body. They are either water-soluble or fat-soluble. A sample of herbal tea, X, was analysed using chromatography with four water-soluble vitamins, P, Q, R and S, using water as the solvent. When the solvent front reached the position indicated, the chromatogram was placed under ultra-violet light. The following diagram shows the chromatogram obtained. What can be deduced from the results? A All vitamins in X are soluble in water. B One of the vitamins in X is not soluble in water. C Vitamin X consists of vitamin Q, R and S. D Vitamin X contains three different components. solvent front start line X P Q R S B.P. : Boiling Point ���

4 5 The diagram below shows the heating curve of substance X. Which of the following represents the arrangement of the particles in substance X? A B C D 6 The chemical symbol of an element is shown below. Which of the following describes how this element achieves a stable electronic configuration? A gain electrons to form positive ion B lose electrons to form negative ions C lose electrons to form positive ions D share electrons to form diatomic molecules X 197 79 temperature (oC) time (min) ���

5 7 The proton number and electron number of some particles are shown below. The symbols used here do not represent the actual chemical symbol of the elements. particle P Q R S proton number 4 15 19 30 electron number 4 18 19 28 Which two particles are found in an ionic compound? A P and R B P and Q C Q and S D R and S 8 The properties of an unknown substance are given below. • low melting and boiling point • low density • good conductor of electricity in solid state Which of the following is the substance? A B C D ���

6 9 Which of the following best explains the reason why the substance with the structure shown below would be a good lubricant? A strong covalent bonds between the layers of atoms B weak forces of attraction between the layers of atoms C weak covalent bonds between the layers of atoms D weak electrostatic forces of attraction between the layers of atoms 10 Which statement about groups in the Periodic Table is correct? A All groups contain both metals and non-metals. B Atoms of the elements in the same group have the same number of total electrons. C Atomic radius decreases down the group. D Ionisation energy decreases down the group. 11 X2 + 2KY à 2KX + Y2 Based on the equation shown above, _________________________________. A the reaction is a redox reaction B the reaction is a metal displacement reaction C X is less reactive than Y D X2 is the reducing agent ���

7 12 The setup below was used to collect the gas produced when an excess magnesium was added to 50 cm3 of 1 mol/dm3 of hydrochloric acid. The time taken for the reaction to be completed was also recorded. The table below shows the results obtained. volume of gas (cm3) 600 time taken for reaction to complete (s) 60 Which of the following would likely be the results obtained when same concentration of propanoic acid is used instead? volume of gas (cm3) time taken for reaction to complete (s) A 300 30 B 300 60 C 600 60 D 600 180 13 In an experiment, 5 cm3 of 1.0 mol/dm3 of sodium hydroxide is gradually added to 10 cm3 of 1.0 mol/dm3 of hydrochloric acid, containing methyl orange indicator. Which change occurs in the mixture? A A white precipitate is formed. B Methyl orange changes in colour. C The concentration of OH- increases. D The concentration of H+ decreases by half. 14 X, Y and Z elements are found in Period 3 of the Periodic Table. X forms an acidic oxide when burnt in oxygen. Y forms a basic oxide when burnt in oxygen. Z forms an amphoteric oxide when burnt in oxygen. What is the order of the three elements across the Periodic Table? A X, Y, Z B X, Z, Y C Y, X, Z D Y, Z, X ���

8 15 Which of the following reactions is unlikely to take place? A Pb2+ (aq) + 2Cl- (aq) à PbCl2 (s) B Fe2+ (aq) + Mg (s) à Mg2+ (aq) + Fe (s) C 2H+ (aq) + Cu (s) à H2 (g) + Cu2+ (aq) D 2H+ (aq) + CO3 2-(aq) à CO2 (g) + H2O (l) 16 In a chemistry experiment, solution X is gradually added to a salt solution Y, followed by the addition of a dilute nitric acid solution. The graph shows how the mass of precipitate formed changes with the addition of the different solutions. Which of the following would produce the graph as shown above? solution X ions present in salt solution Y A aqueous silver nitrate chloride ion and carbonate ion B aqueous silver nitrate nitrate ion and sulfate ion C aqueous barium nitrate sulfate ion and carbonate ion D aqueous barium nitrate sulfate ion and nitrate ion mass of precipitate/ g addition of X addition of dilute nitric acid total volume of solutions added to salt solution Y/cm3 ���

9 17 The table shows the observations made when an aqueous solution X was tested. reagent added observation acidified silver nitrate solution remained colourless. aqueous sodium hydroxide pungent g