Serangoon Prelim 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 28 Aug 2024 1 hour Additional Materials: Multiple Choice Answer Sheet Setter(s): 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 page 20. The use of an approved scientific calculator is expected, where appropriate. This question paper consists of 18 printed pages, including this cover page. For examiner’s use 40

2 1 Magnesium sulfate is prepared by reacting excess magnesium carbonate with dilute sulfuric acid. MgCO3(s) + H2SO4(aq) → MgSO4(aq) + CO2(g) + H2O(l) Which two pieces of apparatus are needed to obtain magnesium sulfate crystals by this reaction? 1 thermometer 2 evaporating dish 3 filter funnel 4 gas syringe A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4 2 An unknown substance melts at -210 oC and boils at -196 oC. Which of the following correctly describes the arrangement and movement of the particles of this substance at -204 oC? arrangement movement A closely packed in a disorderly manner sliding past one another B closely packed in a disorderly manner vibrating about fixed positions C closely packed in an orderly manner sliding past one another D closely packed in an orderly manner vibrating about fixed positions

3 3 The following diagrams can be used to illustrate 1 a mixture of elements and compounds 2 a mixture of elements 3 molecules of an element 4 molecules of a compound What is the correct order of the diagrams? 1 2 3 4 A X W Y Z B X Z W Y C Z Y W X D Z Y X W 4 A new substance was discovered, and a series of experiments were conducted on it. Which observation suggests that the substance cannot be an element? A It has a fixed boiling point. B It dissolves in water to form a yellow-green solution. C When heated strongly, a brown solid and a yellow gas are produced. D When heated in air, it can form oxides with two different chemical formulae. W X Y Z

4 5 An atom of element T has x protons and y nucleons. How many neutrons and electrons are present in a positive ion of another isotope of element T? neutrons electrons A y x – 1 B y – x x + 1 C y – x + 2 x – 1 D y – x + 2 x 6 The diagram of an ion of element Q is shown. In which period and group is element Q found in the Periodic Table? Group number Period number A 1 2 B 1 3 C 18 2 D 18 3 nucleus

5 7 The physical properties of four substances are given below. solid melting point/oC boiling point/oC electrical conductivity in solid in liquid 1 1130 1950   2 –7.2 58   3 300 340   4 660 2470   Which of the following correctly matches the four substances? 1 2 3 4 A aluminium bromine astatine sodium oxide B sodium oxide bromine astatine aluminium C aluminium astatine silicon dioxide sodium oxide D sodium oxide astatine silicon dioxide aluminium 8 Chromium is a metal. The structure of chromium is described as a lattice of positive ions in a ‘sea of electrons’. Which statements about chromium are correct? 1 Chromium conducts heat because the positive ions are free to move. 2 Chromium conducts electricity because the electrons are free to move. 3 Chromium ions are held together because of their attraction for each other. 4 Chromium has a high melting point due to strong electrostatic forces of attraction. A 2 only B 2 and 4 only C 1, 2 and 3 only D 2, 3 and 4 only

6 9 Which of the following explains why graphite and copper can conduct electricity in the solid state? A Both graphite and copper contain mobile electrons. B Both graphite and copper contain mobile ions. C Graphite contains mobile electrons while copper contains mobile ions. D Graphite and copper contain both mobile electrons and mobile ions. 10 The chemical formula of antimony oxide is Sb2O3 and that of potassium phosphate is K3PO4. Which chemical formula is likely to be antimony phosphate? A SbPO4 B Sb 2PO4 C Sb 2(PO4)3 D Sb3PO4 11 Some properties of four elements, P, Q, R and S, are shown in the table. Two of these elements are in Group 1 of the Periodic Table and two are in Group 17. element reaction with water physical state at room temperature P reacts vigorously solid Q does not react with water solid R reacts explosively solid S dissolves giving a coloured solution liquid Which statement is correct? A P is above R in Group 1. B Q is above R in Group 1. C S is below Q in Group 17. D R is below S in Group 17.

7 12 Transition elements can have variable oxidation states. Which pair of compounds show a transition element in two different oxidation states? A Co 2O3 and LiCoO2 B Cu 2O and CuSO4 C K 2CrO4 and CrO3 D NiO and Ni(NO3)2 13 The table shows the pH ranges of an indicator, bromothymol blue. The table shows the pH of four solutions. solution W X Y Z pH 3 5 7 9 Bromothymol blue was added to a solution in a beaker. Which description will not result in a change in colour of the indicator? colour of indicator yellow green blue pH 4 5 6 7 8 9 A Indicator was added to solution Z. Solution W was added to the mixture until in excess. B Indicator was added to solution W. Solution X was added to the mixture until in excess. C Indicator was added to solution X. Solution Y was added to the mixture until in excess. D Indicator was added to solution Y. Solution Z was added to the mixture until in excess. 14 Which equation suggests that a metal oxide, RO, behaves as an amphoteric oxide? A RO (s) + 2H+ (aq)  R2+ (aq) + H2O (l) B RO (s) + 2OH−(aq)  RO22− (aq) + H2O (l) C RO (s) + H2O (l)  R2+ (aq) + 2OH− (aq) D RO (s) + NH4+ (aq)  R2+ (aq) + H2O (l) + NH3 (g)

8 15 Which mixture of solids would react with dilute nitric acid to form two different gases? A copper and magnesium carbonate B copper( II) carbonate and magnesium oxide C copper( II) carbonate and magnesium D copper(II) oxide and magnesium carbonate 16 In an experiment to determine the concentration of hydrochloric acid, a student titrated 25.0 cm3 of hydrochloric acid with 0.1 mol/dm3 aqueous sodium hydroxide, using methyl orange as an indicator. Which step would cause her calculated concentration of hydrochloric acid to be higher than its expected value? A The burette was rinse with distilled water followed by aqueous sodium hydroxide. B The conical flask was rinse with distilled water followed by hydrochloric acid. C The titration reading was taken when methyl orange turns orange. D Reading the burette at an angle. 17 The mineral dolomite is a double carbonate of magnesium and calcium, with the formula CaMg(CO3)2. When 2.00 g of an impure sample of dolomite was completely dissolved in excess hydrochloric acid, 0.45 g of carbon dioxide was given off. What is the percentag