YCKSS Prelim P1

Name: Index Number: Class: YIO CHU KANG SECONDARY SCHOOL O-LEVEL PRELIMINARY EXAMINATION 2024 SECONDARY FOUR EXPRESS CHEMISTRY 6092/01 Paper 1 1 hour 23 August 2024 (Friday) Additional Materials: Optical Answer Sheet (OAS) READ THESE INSTRUCTIONS FIRST Write in soft pencil on the OAS. Do not use staples, paper clips, glue or correction fluid. Write your name, index number and class on the OAS 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 OAS. Read the instructions on the OAS 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 question paper. The use of an approved scientific calculator is expected, where appropriate. A copy of the Periodic Table is printed on page 20. For Examiner’s Use 40 Setter: Mdm Connie Yeo This document consists of 18 printed pages and 2 blank pages.

2 4E PRELIM EXAM 2024 6092/01 1 At which temperature does a dilute solution of sodium chloride begin to boil? A 90oC B 98oC C 100oC D 102oC 2 Samples of pure and impure aspirin were analysed using chromatography. The resulting chromatogram is shown below. The impure sample of aspirin was contaminated with one of the raw chemicals used during production. What is the Rf value of the chemical? A 0.24 B 0.37 C 0.68 D 0.73 solvent front start line 2.2 cm 4.4 cm 6.0 cm Key X = impure aspirin Y = pure aspirin 1.0 cm 0.0 cm

3 4E PRELIM EXAM 2024 6092/01 3 Four mixtures, each containing two substances, are shown in the table. The two substances need to be separated and collected. Which row is correct? mixture separation method A ethanol and methanol evaporation B ink and water chromatography C oxygen and nitrogen fractional distillation D sand and calcium sulfate filtration 4 In which changes do the particles move further apart? 1 A gas is heated from 0oC to 25oC. 2 Iodine vapour coming into contact with cold surface. 3 Pressure is applied to a gas at a constant temperature. 4 Water boiling to form steam.