2022 CWSS Chem Prelims P1

COMMONWEALTH SECONDARY SCHOOL PRELIMINARY EXAMINATION 2022 CHEMISTRY PAPER 1 Name: _____________________________________ ( ) Class: ___________ SECONDARY FOUR EXPRESS Thurs 15 Sep 2022 6092/01 1h 0800 – 0900 h READ THESE INSTRUCTIONS FIRST Write your name, index number and class on the question paper and the OTAS sheet. Write in soft pencil. An approved scientific calculator may be used. There are forty questions in this section. Answer all questions. For each question, there are four possible answers, A, B, C or D. Choose the one you consider correct and record your choice in soft pencil on the OTAS sheet. 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 19. Name of setter: Ms Tian Yilin This paper consists of <19> printed pages including the cover page. [Turn over ���

2 1 Which option shows the correct drying agent and the corresponding gas that can be collected by the method shown in the set up? drying agent gas collected A anhydrous calcium oxide carbon dioxide B anhydrous calcium oxide hydrogen C concentrated sulfuric acid ammonia D concentrated sulfuric acid chlorine 2 Two experiments, experiments 1 and 2, are set up to demonstrate the diffusion of gases. What would happen to the water levels at P and Q in both experiments? experiment 1 experiment 2 A P is higher than Q P and Q remain the same B P is higher than Q P is lower than Q C P and Q remain the same P and Q remain the same D P and Q remain the same P is higher than Q gas in drying agent experiment 1 experiment 2 ���

3 3 The apparatus is used to separate a mixture of ethanol (boiling point 78 oC), propanol (boiling point 97 oC) and butanol (boiling point 118 oC). Which graph shows the change in concentration of ethanol in the distillation flask as the distillation proceeds? A B C D concentration of ethanol concentration of ethanol concentration of ethanol concentration of ethanol ���

4 4 Two students carried out chromatography experiments to examine a urine sample. They used the same urine sample. The chromatograms obtained by the two students are shown in the diagrams. Why are the chromatograms different? A One of the students used a larger amount of urine sample. B One of the students did not use enough solvent. C One of the students added another substance to the urine sample. D The two students used different solvents. 5 The melting and boiling points of carbon tetrachloride are -23 oC and 76 oC respectively. Which diagrams best represent the arrangement of carbon tetrachloride particles as a sample of it is cooled from 80 oC to -20 oC? arrangement at 80 oC arrangement at -20 oC A 1 2 B 4 4 C 3 3 D 4 3 solvent front ���

5 6 Which of the following contains a