2022 TSS Chem Prelims P1

TEMASEK SECONDARY SCHOOL Preliminary Examination 2022 Secondary 4 Express CHEMISTRY 6092/01 Paper 1 1 hour Question Booklet Additional Material: OTAS READ THESE INSTRUCTIONS FIRST Do not open the booklet until you are told to do so. Write your name, index number and class on the Optical Answer Sheet. Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. You are not required to hand in this booklet at the end of the examination. 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 OTAS. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done on this booklet. A copy of the Periodic Table is printed on page 17. This document consists of 17 printed pages and 1 blank page.

2 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. 2 When a covalent liquid boils, its molecules become more widely spaced. Which property of the molecules has the most influence on the energy required to boil a covalent liquid? A the strength of the forces of attraction between the molecules B the reactivity of the molecules C the shape of the molecules D the strength of the covalent bonds in the molecules 3 In which particle are the number of protons, neutrons and electrons all different? 1 Hexane and octane are liquid hydrocarbons that mix together. Which apparatus is used to separate a mixture of these two liquids? A B C D - + 2+

3 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. 4 A student is provided with two drying agents: concentrated sulfuric acid an d calcium oxide. Which method should he use to collect a sample of dry ammonia? A B C D 5 Silicon carbide, SiC, has a structure similar to diamond. Boron nitride, BN, has a structure similar to graphite. Bronze is an alloy of copper and tin. Which statements about SiC, BN and bronze are correct? 1 All are bonded covalently. 2 All have a giant structure. 3 All have high melting points. A 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

4 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. 6 Some car paints contain small flakes of silicon dioxide, SiO2. In the structure of solid SiO2, • each silicon atom is bonded to x oxygen atoms, • each oxygen atom is bonded to y silicon atoms, • each bond is a z type bond. What is the correct combination of x, y and z in these statements? x y z A 2 1 covalent B 2 1 ionic C 4 2