2023 YTSS Chem Prelims P1

NAME: ( ) CLASS: YISHUN TOWN SECONDARY SCHOOL PRELIMINARY EXAMINATION 2023 SEC 4 EXPRESS CHEMISTRY (6092/1) DATE : 30 Aug 2023 DAY : Wednesday DURATION: 1 hr MARKS: 40 marks ADDITIONAL MATERIALS Multiple Choice Answer Sheet (OMS) READ THESE INSTRUCTIONS FIRST Write your name, class and register number in the spaces provided at the top of this page. There are forty questions. 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. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. INFORMATION FOR CANDIDATES Any rough working should be done in this booklet. You may use an approved calculator. A copy of the Periodic Table is printed on the last page. This question paper consists of 16 printed pages 1 A student wanted to collect a dry sample of gas X using the reactants and apparatus below.

2 What is gas X and a suitable drying agent that can be used? Gas X Drying agent A hydrogen chloride calcium oxide B ammonia concentrated sulfuric acid C hydrogen chloride concentrated sulfuric acid D ammonia calcium oxide 2 Three balloons are placed inside plastic containers containing different gases at room temperature and pressure as shown below. I II III Which correctly describes the balloon in each set up after a while? I II III A becomes bigger remains the same deflates B becomes bigger becomes bigger becomes bigger C deflates remains the same becomes bigger D deflates becomes bigger becomes bigger carbon dioxide nitrogen helium hydrogencarbon monoxide neon

3 3 The atmosphere of Venus contains mainly oxygen, argon and nitrogen. The melting and boiling points of these gases are shown in the table below. What temperature should the sample of air be decreased to in order to obtain only liquid oxygen? A -180oC B -185oC C -187oC D -198oC 4 The apparatus shown is used to distil butanoic acid (boiling point 164ºC) from a mixture of butanoic acid and water. Which graph best shows the change in the concentration of the butanoic acid in flask F during the distillation process? gas melting point / oC boiling point / oC oxygen -219 -183 argon -189 -186 nitrogen -210 -196 A B C D

4 5 Which solution when added to both the reagents below will produce a gas? • Sodium carbonate • Aqueous sodium hydroxide with aluminium foil A dilute nitric acid B aqueous ammonium nitrate C dilute sulfuric acid D aqueous potassium sulfate 6 Ions of two isotopes of nickel are shown below. They are labelled as X and Y. X Y Which statement is correct about these ions? A Both ions have the same number of electrons b