2022 PSS Chem Prelims P1

1 Class Register Number Candidate Name PEIRCE SECONDARY SCHOOL Department of Science GCE ‘O’ Level Preliminary Examination I for Secondary Four Express CHEMISTRY 6092 Wednesday 9 May 2018 0900 – 1000 Time: 1 hour INSTRUCTIONS TO CANDIDATES Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, Index number on the Answer Sheet in the spaces provided. 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 the separate answer sheet. INFORMATION FOR CANDIDATES 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 19. This paper consists of 15 printed pages. Setter: Mr Ashwin Selvarajan ���

2 1 Gas W is contaminated with another gas. The impure gas can be removed using liquid Z. Which apparatus is most suitable for the collection of pure gas W? Impure gas W Impure gas W Impure gas W Impure gas W Liquid Z Liquid Z Liquid Z Liquid Z A B C D ���

3 2 Small crystals of red cobalt(II) nitrate and blue copper(II) sulfate were placed at the centers of separate petri dishes filled with agar jelly. They were left to stand under the same physical conditions. After some time, the colour of each substance has spread out as shown. Dish 1 Dish 2 The lengths of the arrows indicate the relative distances travelled by particles of each substance. Which statement is correct? A Diffusion is faster in dish 1 because the mass of the particles is greater. B Diffusion is faster in dish 2 because the mass of the particles is smaller. C Diffusion is slower in dish 1 because the mass of the particles is smaller. D Diffusion is slower in dish 2 because the mass of the particles is greater. 3 A scientist wishes to separate a mixture of iodine, magnesium chloride and lead(II) chloride. Which of the following is the most appropriate sequence of techniques for the scientist to use? Step 1 Step 2 Step 3 A sublimation dissolution and filtration crystallisation B sublimation fractional distillation dissolution and filtration C dissolution and filtration crystallisation sublimation D dissolution and filtration fractional distillation crystallisation ���

4 4 The following diagrams show the arrangement of parti