Bowen 5105 Sci Chemistry Paper 3

Class Full Name Index Number PRELIMINARY EXAMINATION 2023 I believe, therefore I am SCIENCE (CHEMISTRY) Paper 3 Multiple Choice Secondary 4 Normal Academic Additional materials: Multiple Choice Answer Sheet Papers 3 and 4: 1 hour 15 minutes 28 July 2023 READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, class and index number on all the work you hand in. There are twenty 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. Answers to Paper 3 and Paper 4 must be handed in separately. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. You are advised to spend no more than 30 minutes on Paper 3. You may proceed to answer Paper 4 as soon as you have completed Paper 3. Any rough working should be done in the booklet. A copy of Periodic Table is printed on page 9. The use of an approved scientific calculator is expected, where appropriate. DO NOT OPEN THIS PAPER UNTIL YOU ARE TOLD TO DO SO For Examiner’s Use This document consists of 9 printed pages, including the cover page and a copy of Periodic table N 5105/5107/03 20

2 [Turn over 1. Substance X and substance Y are compounds found in a food sample . Both are liquids at room temperature with different boiling points. Which of the following is the most suitable method to separate a mixture of X and Y to obtain each substance respectively? A C B D 2. Which statement shows that a sample of water is pure? A It has no effect on both red and blue litmus papers. B It is colourless and odourless. C It boils exactly at 100°C. D It has a density of 1g/dm3.

3 [Turn over 3. The table below shows information about three different substances. substance decompose upon heating solubility in water solubility in alcohol P no no no Q no no yes R yes yes no Which of the following shows the correct steps to take to separate and obtain a sample of substance R from a mixture of these three substances? A dissolving the mixture in alcohol → filtration → evaporation to dryness B dissolving the mixture in alcohol → filtration → crystallisation C dissolving the mixture in water → filtration → evaporation to dryness D dissolving the mixture in water → filtration → crystallisation 4. Which statement best expla ins why carbon dioxide gas does not have a fixed volume and can be compressed easily? A The attractive forces between the particles are weak. B The particles are able to move freely and randomly