2022 YHSS Chem Prelims P1

YUHUA SECONDARY SCHOOL PRELIMINARY EXAMINATION 2022 SECONDARY FOUR EXPRESS CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY 6092/01 Paper 1 Multiple Choice 29 August 2022 1 hour Additional Materials : Multiple Choice Answer Sheet Setter: Ms Cerenna Ng READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your Name, Class and Class 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 16. The use of an approved scientific calculator is expected, where appropriate. This document consists of 16 printed pages, inclusive of this page. [Turn over

2 YHSS/Prelims/2022 Secondary Four Express Chemistry (Paper 1) 1 Liquid ethylamine and hydrochloric acid are volatile substances. Ethylamine gas, C2H5NH2, and hydrogen chloride gas, HCl, react to form a white solid, ethylamine hydrochloride. At which position in the tube would a ring of white solid ethylamine hydrochloride form? 2 The diagram shows a method to collect a dry sample of gas Z. Which information can be deduced about gas Z? 1 Z is an alkaline gas. 2 Z is less dense than air. 3 Z is very soluble in water. A 2 only B 1 and 2 only C 2 and 3 only D 1, 2 and 3 A B C D cotton wool soaked in liquid ethylamine cotton wool soaked in concentrated hydrochloric acid concentrated sulfuric acid Y Y gas Y dry sample of gas Y dry sample of gas Z gas Z concentrated sulfuric acid

3 YHSS/Prelims/2022 Secondary Four Express Chemistry (Paper 1) [Turn Over 3 A series of experiments was conducted on a newly discovered substance. Which observation suggests that the substance cannot be an element? A Electrolysis of the molten substance produces two products. B The substance dissolves in water to give a colourless solution. C The substance has a fixed melting point. D When the substance is heated in air, a white solid is formed. 4 In an experiment, a solid P is found to melt at 121 °C, the same temperature as the melting point of benzoic acid. In another experiment, some solid P is mixed with pure solid benzoic acid. The melting point of the mixture is found to be 116 °C. What can be concluded from the two experiments? A P is a mixture. B P is not benzoic acid. C P is a pure compound. D P is impure benzoic acid. 5 Compound A consists of a lattice of positive ions of Y and negative ions of Z. Each positive ion is surrounded by eight negative ions and each negative ion is surrounded by four positive ions. Which option correctly shows the chemical formula of compound A and ions present in compound A? chemical formula ions present A YZ2 Y2+, Z- B Y2Z Y+, Z2- C ZY2 Y2+, Z- D Z2Y Y+, Z2-

4 YHSS/Prelims/2022 Secondary Four Express Chemistry (Paper 1) 6 An atom of one isotope of uranium is represented by the symbol U92235. Which row is correct for an atom of a different isotope of uranium? nucleon number number of protons number of neutrons A 147 92 147 B 239 92 147 C 235 92 143 D 239 147 239 7 Dilute sulfuric acid is added to a mixture of excess copper, excess magnesium, and excess lead in a beaker. The beaker is left for about 10 minutes and its contents are then filtered. What does the filtrate contain? A copper(II) sulfate, magnesium sulfate, and lead(II) sulfate B copper(II) sulfate and magnesium sulfate C lead(II) sulfate and magnesium sulfate D magnesium sulfate 8 Silicon and carbon are in the same group of the Periodic Table. Which chemical formula containing silicon is incorrect? A CaSiO2 B SiCl4 C SiH4 D SiHCl3 9 Element Z forms an ion with 2+ charge. An ion of Z has a nucleon number of 226 and 86 electrons. Which statement about an ion of Z Is correct? A It has 140 neutrons. B It has 2 electrons in its valence shell. C It has 86 protons. D It has the same number of nucleons as an atom of Z.

5 YHSS/Prelims/2022 Secondary Four Express Chemistry (Paper 1) [Turn Over 10 A student wants to prepare calcium sulfate. Which pair of reagents are the most suitable for making calcium sulfate? A calcium and sulfuric acid B calcium carbonate and sulfuric acid C calcium nitrate and sulfuric acid D calcium oxide and sulfuric acid 11 Which gas contains the same number of atoms as 9 g of water? A 1 g of hydrogen B 15 g of neon C 24 g of ozone D 44 g of carbon dioxide 12 The combustion reaction of ammonia gas and carbon are shown below. Reaction 1: 4NH3 (g) + 3O2 (g) → 2N2 (g) + 6H2O (l) Reaction 2: C (s) + O2 (g) → CO2 (g) 80 cm3 of ammonia burns in 80 cm3 of oxygen and the resulting gas mixture is reacted with an excess of carbon. What is the total volume of gases that would be collected at the end of the second reaction? A 20 cm3 B 40 cm3 C 60 cm3 D 160 cm3 13 Zinc oxide has antibacterial properties and is commonly used in the treatment of skin conditions. Zinc oxide reacts with hydrochloric acid according to the equation shown below. ZnO + 2HCl → ZnCl2 + H2O When 19 g of impure zinc oxide was reacted with excess hydrochloric acid, 23 g of zinc chloride was formed. What is the percentage purity of the zinc oxide used? A 42.9 % B 59.5 % C 72.1 % D 82.6 %

6 YHSS/Prelims/2022 Secondary Four Express Chemistry (Paper 1) 14 Each of the following solutions has a concentration of 0.5 mol/dm3. Which solution contains the greatest number of ions in 1 dm3 of solution? A calcium hydroxide B ethanoic acid C ethanol D nitric acid 15 Chromium(III) sulfate reacts with sodium carbonate to produce a precipitate of chromium(III) carbonate. Which row shows the solubility of chromium(III) sulfate, sodium carbonate and chromium(III) carbonate? chromium(III) sulfate sodium carbonate chromium(III) carbonate A insoluble soluble insoluble B soluble soluble insoluble C insoluble insoluble soluble D soluble soluble soluble 16 What does the term strong acid mean in relation to hydrochloric acid, HCl? A Each molecule can produce two hydrogen ions. B It is fully ionised in aqueous solution. C Its aqueous solution has a pH greater than 7. D Its salt, lead(II) chloride, is insoluble in water. 17 Imidazole dissolves in water to give a weak alkaline solution. A few drops of Universal Indicator are added to an aqueous solution of imidazole. Which row shows the pH of the solution and the colour of the solution after the indicator has been added? pH colour of solution A greater than 7 blue B greater than 7 purple C less than 7 blue D less than 7 purple

7 YHSS/Prelims/2022 Secondary Four Express Chemistry (Paper 1) [Turn Over 18 The reaction represented by the following equation occurs by collisions between X2 and Y2 molecules. X2 (g) + Y2 (g) à 2XY (g) Which statement(s) is/are correct? 1 All collisions between X2 and Y2 molecules produce XY molecules. 2 The frequency of collisions is increased by raising the concentration of X2 and Y2 molecules in the reaction mixture. 3 The frequency of collisions is unaffected by raising the pressure exerted on the reaction mixture. 4 The frequency of collisions is increased by a rise in the temperature of the react