2022 PYSS Chem Prelims P1

[Turn over This exam paper is the property of Ping Yi Secondary School. It must not be duplicated in part or whole. This document consists of 18 printed pages including this cover page and inserts. ‘Perseverance Yields Success’ Ping Yi Secondary School PRELIMINARY EXAMINATION 2022 Secondary 4 Express Chemistry 6092/01 Paper 1 Multiple Choice 1 hour Additional materials: Multiple Choice Answer Sheet INSTRUCTIONS TO CANDIDATES Do not open this booklet until you are told to do so. Write your name, class and register number in the spaces at the top of this page. You may use a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, glue or correction fluid. There are forty questions in 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 Optical Answer Sheet (OAS). 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 Data Sheet is printed on page 17. A copy of the Periodic Table is printed on page 18. Expected Grade □ A1 □ A2 □ B3 □ B4 □ C5 Teacher’s Comment Student’s Comment Parent’s Comment and Signature ���

2 [Turn Over This exam paper is the property of Ping Yi Secondary School. It must not be duplicated in part or whole. Answer all the questions in the answer sheet provided. 1 The diagram shows an experiment to find the formula of magnesium oxide. Which piece of apparatus would be needed in addition to those shown above? A burette B electronic balance C measuring cylinder D thermometer 2 Which of the following substances may be condensed using a water condenser? substance melting point / °C boiling point / °C A ammonia -78 -33 B butane -135 -0.5 C hydrogen chloride -115 -85 D pentane -130 36 3 Which 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 close together, moving at random B widely separated, not moving widely separated, moving at random C widely separated, moving at random close together, moving at random D widely separated, moving at random close together, not moving 4 At which temperature does a concentrated aqueous solution of sodium chloride begin to boil? A 93 ⁰C B 99 ⁰C C 100 ⁰C D 104 ⁰C ���

3 [Turn Over This exam paper is the property of Ping Yi Secondary School. It must not be duplicated in part or whole. 5 The diagram shows the apparatus used to obtain carbon monoxide. What is the main purpose of Y? A to dry the gas B to prevent water from being sucked back into the hot carbon C to remove carbon dioxide from the gas D to remove hydrogen chloride from the gas 6 The nucleon number and proton number of an atom of X and an atom of Y are shown. X Y proton number 19 17 nucleon number 39 37 The following statements are made on X and Y. 1 An ion of X has more electrons than an ion of Y. 2 Both ions have the same number of valence electrons. 3 Both ions have the same number of neutrons. 4 Both react together to form a covalent compound XY. Which statement(s) is/are correct? A 1 only B 1 and 2 only C 2 and 3 only D 3 and 4 only ���

4 [Turn Over This exam paper is the property of Ping Yi Secondary School. It must not be duplicated in part or whole. 7 The diagrams show the electronic structures of four elements. The following statements are made on the four elements. 1 Elements 1 and 2 are good electrical conductors. 2 Elements 2 and 4 have very high melting points. 3 Element 2 is more reactive than element 4. 4 Element 4 has a giant lattice structure. Which statement(s) is/are true about the four elements? A 1 only B 2 and 3 only C 2 and 4 only D 3 and 4 only 8 Carbon disulfide is a simple covalent compound used in manufacturing polymers. Which of these statements would you predict to be true about carbon disulfide? A It has a low boiling point and conducts electricity when molten. B It has a low boiling point and is soluble in organic solvents. C It is a crystalline solid at room temperature and conducts electricity when molten. D It is a crystalline solid at room temperature and is soluble in organic solvents. 9 In which pair of covalent molecules does oxygen form at least one double bond on both molecules? A CO2 and C2H5OH B CO2 and O2 C H2O and C2H5OH D H2O and O2 10 The formula of thallium carbonate is Tl2CO3 and that of sodium chlorite is NaClO2. What is the formula of thallium chlorite? A TlClO2 B Tl2ClO2 C Tl(ClO2)2 D Tl2(ClO2)3 Element 1 Element 2 Element 3 Element 4 ���

5 [Turn Over This exam paper is the property of Ping Yi Secondary School. It must not be duplicated in part or whole. 11 Which molecule has the least number of electrons involved in covalent bonds? A C2H2 B C2H4 C H2S D N2 12 Which statement best explains why graphite is often employed as a dry lubricant in hot machines? A Each carbon atom uses only three out of four valence electrons for bonding. B The carbon atoms in each layer are held by weak covalent bonds. C The carbon atoms in graphite are connected in a tetrahedral arrangement. D The different layers of carbon atoms are held by weak intermolecular forces of attraction. 13 Silicon carbide has a structure similar to diamond. Boron nitride has a structure similar to graphite. Bronze is a mixture of metals. Which statements about silicon carbide, boron nitride and bronze are correct? 1 All are bonded covalently. 2 All are insoluble in water. 3 All except silicon carbide conduct electricity when solid. 4 Bronze has low melting point. A 1 and 2 B 2 and 3 C 2 and 4 D 3 and 4 14 In an experiment, excess hydrochloric acid was added to 0.5 g of chalk and 100 cm3 of carbon dioxide was produced at room temperature and pressure. What is the percentage purity of calcium carbonate in the sample of chalk? A 1.20 % B 2.20 % C 41.7 % D 83.3 % 15 In which reaction does the smallest percentage change in volume occur? A CH4(g) + 2O2(g) → CO2(g) + 2H2O(l) B C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(l) C 2H2S(g) + SO2(g) → 3S(s) + 2H2O(l) D 4NH3(g) + 3O2(g) → 2N2(g) + 6H2O(l) ���

6 [Turn Over This exam paper is the property of Ping Yi Secondary School. It must not be duplicated in part or whole. 16 Dilute sulfuric acid was added to aqueous barium hydroxide until the acid was in excess. Which graph shows the variation in the total number of ions in the solution? 17 49.2 g of hydrated magnesium sulfate is heated and cooled repeatedly until it reaches a constant mass of 24.0 g. Assuming only water of crystallisation is lost when hydrated magnesium sulfate is heated, what is the formula of the hydrated magnesium sulfate? A MgSO4.3H2O B MgSO4.5H2O C MgSO4.7H2O D MgSO4.10H2O ���

7 [Turn Over This exam paper is the property of Ping Yi Secondary School. It must not be duplicated in part or whole. 18 A pH probe measures the pH changes during a titration experiment. In the experiment, an unknown acid, HX of concentration 0.1 mol/dm3, was added from a burette to 25.0 cm3 of dilute sodium hydroxide. The graph shows the results of the experiment. Which statement about the results obtained from the experiment is incorrect? A Concentration of alkali used is less than 0.1 mol / dm3. B Formula of salt formed is NaX. C HX is a strong acid. D Neutralisation only occurs when 20.0 cm3 of HX is added to sodium hydroxide. 19 A sample of 0.5 g of magnesium ribbon is reacted with an excess of 1.0 mol/dm3 hydrochloric acid. The volume of hydrogen gas produce over time i