2022 QSS Chem Prelims P1

This document consists of 17 printed pages. Name: ………………………………………………….. ( ) Class: Sec 4A Queenstown Secondary School Preliminary Examination 2022 Secondary Four Express Chemistry 6092/01 31 August 2022 Time: 1200 – 1300h Wednesday Duration: 1 hour Additional Materials: Multiple Choice Answer Sheet 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. 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 17. The use of an approved scientific calculator is expected, where appropriate. ���

2 Queenstown Secondary School [Turn over 1 Silica gel is a solid which can absorb water vapour from the air. It can be used to limit the growth of mould on leather goods and electronic equipment. Which of the following methods can be used to study the rate of absorption of water vapour in silica gel? A C B D 2 A liquid mixture contains methylbenzene and dilute aqueous copper(II) sulfate with different densities. Methylbenzene has a boiling point of 111oC and is insoluble in water. Which of the following steps can be used to obtain a liquid sample of methylbenzene and solid sample of copper(II) sulfate? step 1 step 2 A fractional distillation crystallisation B simple distillation evaporation C use a separating funnel crystallisation D use a separating funnel evaporation ���

3 Queenstown Secondary School [Turn over 3 During the test for chloride ion using aqueous silver nitrate, the solution must be acidified with dilute nitric acid. What is the purpose of adding dilute nitric acid? A To oxidise the chloride ion. B To increase the speed of reaction. C To prevent the precipitation of other ions. D To prevent the decomposition of silver chloride formed. 4 In an experiment, 4.0 cm3 of 1.0 mol/dm3 aqueous copper(II) sulfate and 8.0 cm3 of 1.0 mol/dm3 aqueous barium nitrate are mixed. CuSO4 (aq) + Ba(NO3)2 (aq) → Cu(NO3)2 (aq) + BaSO4 (s) What does the reaction vessel contain once the reaction is complete? A a colourless solution only B a white precipitate and a blue solution C a blue p