Whitley Prelim P1

Name: ( ) Class: WHITLEY SECONDARY SCHOOL A Caring and Learning Community of Leaders Perseverance * Respect * Integrity * Discipline * Empathy PRELIMINARY EXAMINATION 2024 READ THESE INSTRUCTIONS FIRST Write your name, class and index number in the spaces at the top of this page. 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 unless this has been done for you. There are forty questions. 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 16. The use of an approved scientific calculator is expected, where appropriate. This paper consists of 16 printed pages. SUBJECT : Chemistry (6092/01) LEVEL : Secondary 4 Express DATE : 23 August 2024 DURATION : 1 hour SETTER : Mrs Ambikai VETTERS : Ms Charlene Lye and Mr Ng Mun Leong

2 2 1. Stearic acid has a melting point of 69oC. A heated sample of pure stearic acid is cooled and the temperature is recorded every minute for 30 minutes. A graph of the results is shown. Which process occurs between 8 and 12 minutes? A boiling B condensing C freezing D melting 2. Two samples of a colourless solution are tested separately with aqueous sodium hydroxide, NaOH(aq), and aqueous ammonia, NH3(aq), and the results are recorded.  A white precipitate is formed with two drops of NaOH(aq). This precipitate dissolves in an excess of NaOH(aq).  A white precipitate is formed with two drops of NH3(aq). This precipitate dissolves in an excess of NH3(aq). What can be deduced from these results? A The anion present is Cl-. B The anion present is not Cl-. C The cation present is Al3+. D The cation present is Zn2+.

3 3 3. A student uses paper chromatography to find an Rf value for Fe3+(aq). The result is shown. To make the spot containing Fe3+(aq) more visible, the paper is sprayed with aqueous sodium hydroxide so that a precipitate of iron(III) hydroxide forms. Under the conditions of the experiment, the Rf value of Fe3+(aq) is given by …..1….. The colour of the precipitate is …..2….. . Which row correctly completes gaps 1 and 2? 1 2 A 𝑥𝑦 green B 𝑥𝑦 red-brown C 𝑦𝑥 green D 𝑦𝑥 red-brown

4 4 4. The diagram shows a diffusion experiment. Which gas, when present in the beaker over the porous pot, will cause the water level at Y to rise? A carbon dioxide B chlorine C methane D nitrogen dioxide 5. Two particles have the symbols Fe