2022 TPSS Chem Prelims P1

This document consists of 17 printed pages. © TPSS/6092/2022/SEC4E/PE TAMPINES SECONDARY SCHOOL Secondary Four Express PRELIMINARY EXAMINATIONS 2022 NAME CLASS REGISTER NUMBER CHEMISTRY 6092 / 01 Paper 1 14 Sep 2022 1 hour Additional Materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Do not open this booklet until you are told to do so. Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your class, index number and name on the Answer Sheet 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 Multiple Choice Answer Sheet. INFORMATION FOR CANDIDATES The number of marks is given in brackets [ ] at the end of each question or part question. Use of calculator is allowed. Each correct answer will score one mark. No marks will be deducted for a wrong answer. A copy of the Periodic Table is printed on page 17. The use of an approved scientific calculator is expected, where appropriate. For Examiner’s Use Paper 1 (40 marks) [Turn over O ���

2 1 A student put exactly 25.0 cm3 of dilute hydrochloric acid into a conical flask. The student added 2.5 g of solid sodium carbonate and measured the change in temperature of the mixture. Which apparatus does the student need to use? A balance, measuring cylinder, thermometer B balance, pipette, stopwatch C balance, pipette, thermometer D burette, pipette, thermometer 2 The diagram below shows a set-up to prepare a dry sample of ammonia gas. The experiment failed. What modifications should be done to correct the set-up? 1 An alkali should be placed in the test-tube instead of an acid. 2 Anhydrous calcium oxide should be used instead of concentrated sulfuric acid. 3 The gas should be collected in a gas syringe instead of by displacement of water. A 1 only B 3 only C 1 and 2 only D 1, 2 and 3 ���

3 3 Which statement best explains why two liquids can be separated by fractional distillation? A Both have different boiling points. B Both have different densities. C Both have different masses. D Both have different reactivities. 4 A student carried out a chromatography of a sample to separate amino acids present. He performed a second chromatography experiment on the sample. The following shows the two chromatograms obtained. Why do the two chromatograms show different results? A The solvent moved up the paper at different speeds. B Different solvents were used for the two experiments. C The sample for the second experiment was contaminated. D The sample for the second experiment was more concentrated. 5 Which of the following steps can be used to separate sodium sulfate from calcium sulfate? A dissolving in water → filtration → distillation of filtrate B dissolving i