Punggol Prelim P1

EXP PUNGGOL SECONDARY SCHOOL SECONDARY 4 EXPRESS 2024 PRELIMINARY EXAMINATION QUESTION & ANSWER BOOKLET NAME CLASS INDEX NUMBER Chemistry Paper 1 6092 27 August 2024 Additional materials: MCQ answer Sheet 1 hour READ THESE INSTRUCTIONS FIRST Write your class, register number and name on all the work you hand in. Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. 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 18. The use of an approved scientific calculator is expected, where appropriate. For Examiner’s use Parent’s Signature - - - - - - Total /40 This paper consists of 18 printed pages and 0 blank page.

2 1 The diagram shows the apparatus used to obtain pure water from tap water and concentrated salt solution. What are the possible temperatures indicated at X, Y and Z? X Y Z A 100 °C 100 °C 100 °C B 100 °C 100 °C 105 °C C 95 °C 100 °C 105 °C D 105 °C 95 °C 100 °C

3 2 The diagram shows a beaker full of gas X inverted over a porous pot containing gas Y. A known liquid is used in the container. None of the gases provided below are soluble in the liquid. Which pair of gases will lead to the liquid spilling out at the outlet O? Gas X Gas Y A chlorine helium B argon hydrogen C flourine helium D neon chlorine 3 Products made of plastics have greatly improved our daily lives. Plastics can be made from fractions derived from crude oil. 1 Plastics are mixtures of substances with different boiling points. 2 Crude oil is a mixture of substances with different boiling points. 3 The chemical composition of the recycled plastics remains unchanged using the chemical method of recycling plastics. 4 Plastics such as poly(ethene) is an example of addition polymer. Which statements about plastics and crude oil are correct? A 2, 3 and 4 only B 1, 3 and 4 only C 2 and 4 only D 1 and 3 only

4 4 Salicylic acid is a substance used in skin ointments and a sample of it is found to contain impurities like iron and sodium iodide. Salicylic acid sublimes at 76 oC and is soluble in water. What is the best method to obtain pure salicylic acid from the sample? A Add water, filter and evaporate B Add water, filter and sublime C Use magnets, add water and filter D Add water, filter, crystallise and sublime 5 An ion R2− contains 45 neutrons and 3