2023 WDL Chem Prelims P1

EXPRESS EXPRESS EXPRESS Name: ………………………………..…..( ) Class: …………. WOODLANDS SECONDARY SCHOOL PRELIMINARY EXAMINATION 2023 Level: Secondary Four Express Marks: 40 Subject: Chemistry Day: Tuesday Paper: 6092/01 Date: 22 August 2023 Duration: 1 hour Time: 1135 – 1235 _____________________________________________________________________ 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 the Answer Sheet in the spaces provided unless this has been done for you. 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 Answer Sheet. Read the instructions on the Answer Sheet 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 20. The use of an approved scientific calculator is expected, where appropriate. At the end of the examination, submit the OTAS separately from the question paper. DO NOT TURN THE PAGE UNTIL YOU ARE TOLD TO DO SO. This document consists of 20 printed pages.

2 6092/01/Prelim/2023 EXPRESS EXPRESS EXPRESS 1 The diagram below shows the setup for a chemical reaction which produces a gas. The gas is then dried and collected. What could the gas be? A carbon dioxide B hydrogen C oxygen D sulfur dioxide 2 Gore-Tex fabric is a water-resistant and breathable material often used in outdoor sportswear. It can block out rainwater while allowing water vapour from body perspiration to escape. Its structure consists of a few layers of porous membranes, each with pores of different sizes. Which of the following explains how the fabric can be water-resistant and yet breathable? A The pores in the layers are smaller than liquid water droplets and water vapour molecules. B The pores in the layers are bigger than liquid water droplets and water vapour molecules. C The pores in one layer are smaller than liquid water droplets while the pores in other layers are bigger than water vapour molecules. D The pores in one layer are bigger than liquid water droplets while the pores in other layers are smaller than water vapour molecules.

3 6092/01/Prelim/2023 EXPRESS EXPRESS EXPRESS 3 The diagram below shows the solubility curves of 3 salts, P, Q and R over a range of temperatures. P, Q and R were added to separate beakers of water. Which of the following shows the best method of obtaining a so