2023 ZHSS Chem Prelims P1

1 [Turn Over ZHONGHUA SECONDARY SCHOOL PRELIMINARY EXAMINATION 2023 SECONDARY 4 EXPRESS Candidate’s Name Class Register Number 4E CHEMISTRY 6092/01 25 Aug 2023 1 hour Additional Materials: OTAS READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, index number and class on the OTAS in the spaces provided. 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 OTAS. 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 16. This document consists of 16 printed pages.

1 A student measured the rate of reaction between calcium carbonate and dilute hydrochloric acid. A graph showing the volume of gas produced against time is shown. Which apparatus was used to measure the variables shown on the graph? A burette and stopwatch B electronic balance and burette C electronic balance and gas syringe D gas syringe and stopwatch 2 The diagram below shows the apparatus used to obtain the gas carbon monoxide. What is the main purpose of solution W? A It is to remove carbon dioxide from the gas. B It is to remove hydrogen chloride from the gas. C It is to remove nitrogen from the gas. D It is to remove water vapour from the gas. solution W calcium carbonate water carbon monoxide lumps of charcoal dilute hydrochloric acid

3 [Turn Over 3 The diagram below shows the chromatogram of some metal ions during an investigation. Which spot corresponds to Cu2+ if it has a Rf value of 0.4? 4 Which reagent(s) can be used to distinguish between aqueous zinc nitrate and aqueous calcium chloride? 1 aqueous sodium carbonate 2 aqueous lead(II) nitrate 3 dilute sulfuric acid A 1 only B 1 and 3 C 2 and 3 D 1, 2 and 3 A B C D

5 The table shows the melting points and boiling points of some substances. substance melting point / °C boiling point / °C S T U V 8 660 -3 -185 79 1314 105 -84 Which statement on the physical state of the substance is correct? A S is a solid at 25 °C. B T is a liquid at 25 °C. C U is a gas at 100 °C. D V is a gas at 100 °C. 6 Which set of three particles have the same total number of electrons? A Cl- Br - I- B F- Ne Na+ C K+ Ca2+ Br- D Li+ Na+ K+ 7 Unknown elements X and Y form an ionic compound X2Y. What is the correct electron arrangement of the atoms