2022 OPSS Chem Prelims P2

ORCHID PARK SECONDARY SCHOOL Preliminary Examination 2022 CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY Paper 2 Secondary 4 Express Setter: Mr Goh Chye Joo 6092/02 24 August 2022 1 hour 45 minutes 80 Marks Additional Materials: Nil READ THESE INSTRUCTIONS FIRST Write your name, register number and class on all the work you hand in. Write in dark blue or black ink. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Section A Answer all questions in the spaces provided. Section B Answer all three questions. The last question is in the form either/or. Answer all questions in the spaces provided. The number of marks is given in brackets [ ] at the end of each question or part question. A copy of the Periodic Table is printed on page 18. The use of an approved scientific calculator is expected, where appropriate. This document consists of 18 printed pages. [Turn over

2 Section A Answer all questions in the space provided. The total mark for this section is 50. A1 This table shows some information about atoms of the elements L, M, N and O. (The letters do not represent the atomic symbols of the elements.) element atomic number number of protons number of neutrons mass number electronic configuration L 16 16 16 32 M 7 7 7 14 N 1 1 1 2 1 O 11 (a) (i) Complete the table by filling in the information of the four elements. [3] (ii) Give a reason why element O is likely to be a metal. ……………………………………………………………………..……………... ……………………………………………………………………………………. [1] (b) (i) Describe the change in electronic configuration that occurs to an atom of element M when it forms an ion. State the formula of ion formed using the chemical symbol M. ……………………………………………………………………..……………... ……………………………………………………………………………………. [2] (ii) The accurate relative atomic mass of element L is 32.1. Explain why this is not a whole number. ……………………………………………………………………..……………... ……………………………………………………………………………………. [1] (c) Draw a dot and cross diagram to show the bonding formed between element N and O. Show outer electrons only. [2]

3 A2 Iron is one of the most important metals. Most iron is used in the alloy steel. (a) Explain, in terms of metallic bonding, why iron is a good electrical conductor. …………………….………………………………………………...……………………. ……………………………………………………………………………………………. …………………….………………………………………………...……………………. ……………………………………………………………………………………………. [2] (b) Describe how different proportions of carbon can modify the physical properties of steel. …………………….………………………………………………...……………………. ……………………………………………………………………………………………. …………………….………………………………………………...……………………. ……………………………………………………………………………………………. [2] (c) When under water, iron pipes will rust relatively rapidly. (i) State the essential conditions needed for the