2022 AMKSS Chem Prelims P1

1 Name Class Index Number ANG MO KIO SECONDARY SCHOOL PRELIMINARY EXAMINATION 2022 SECONDARY FOUR EXPRESS CHEMISTRY 6092 /01 Total Mark: 40 31 August 2022 / Wednesday Setters: Ms Tay Siew Peng 1 hour Additional Materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Write your Name, Class and Index Number in the spaces on the Multiple Choice Answer Sheet. Do not use staples, paper clips, glue or correction fluid/tape. 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 Multiple Choice Answer Sheet. Read the instructions on the Multiple Choice 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 15. The use of an approved scientific calculator is expected, where appropriate. For Examiner’s use TOTAL This document consists of 15 printed pages, including the cover page. [Turn over] �

2 1 A student has to measure 30.60 cm3 of aqueous sodium bromide solution. Which apparatus should the student select? A B C D 2 Caffeine is a white solid that melts at 235 °C. A sample of impure caffeine is found to be contaminated with sugar. Propanone is an organic solvent with a low boiling point. Caffeine and sugar have different solubilities in water and propanone. substance solubility in water solubility in propanone caffeine moderate high sugar high insoluble The following steps could be carried out to obtain pure caffeine from a mixture of caffeine and sugar. I add excess water II add excess propanone III cool and crystallise IV filter the mixture V heat the filtrate In what order should the steps be carried out? A I, IV, III and V B I, IV, V and III C II, IV, III and V D II, IV, V and III �

3 3 Distillation is used to obtain water from a copper(II) sulfate solution. Which graph shows the change in concentration of the copper(II) sulfate solution in the distillation flask? A B C D 4 A new substance was discovered and a series of experiments were conducted on it. Which observation suggests that the substance cannot be an element? A It has a fixed boiling point. B It dissolves in water to form a yellow-green solution. C When heated strongly, a brown solid and a yellow gas are produced. D When heated in air, it can form oxides with two different chemical formulae. 5 Three atoms are shown. 32 16 X 33 16 Y 32 17 Z What can be deduced from the proton numbers and