NYGH 2021-S3EOY-IP Chem P2

Class Register Number Name End-of-Year Examination 2021 Secondary 3 IP CHEMISTRY Paper 2 1hour 45 minutes Wednesday 6 October 0845 – 1030 READ THESE INSTRUCTIONS FIRST Write your name, register number and class in the spaces at the top of this page. Write in dark blue or black pen. You may use a pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid / tape. Section A Answer all questions in the spaces provided. You are advised to spend no longer than 1 hour on Section A, and no longer than 45 minutes on Section B. The number of marks is given in brackets [ ] at the end of each question or part question. A copy of the Periodic Table is on page 12. The use of an approved scientific calculator is expected, where appropriate. Section A (40 marks) Section B (30 marks) Total (70 marks) This document consists of 12 printed pages and 0 blank pages. Setter(s): FKD/JK NANYANG GIRLS' HIGH SCHOOL [Turn over A

2 Setters: FKD/JK Chemistry Paper 2 Section A (40 marks) Answer all questions. Write your answers in the spaces provided. A1 Group 17 elements show trends in their melting points and boiling points. Table 1 element melting point/oC boiling point/ oC chlorine 101 35 bromine 7 59 iodine 114 184 (a) The change in temperature against time graph for bromine is represented in Figure 1. Figure 1 (i) State the process occurring at point DE. Hence, explain why temperature remained unchanged. [3] Temperature Time A B C D E F

3 Setters: FKD/JK Chemistry Paper 2 [Turn Over (ii) Describe the arrangement and movement of the particles at point A. [2] (b) Describe and explain the trend in boiling point down the group 17 elements. [3] Total [8]

4 Setters: FKD/JK Chemistry Paper 2 A2 The radii of atoms and ions can be measured. Table 2 shows information about atomic radii and ionic radii of some of the group 1 elements. Table 2 element number of protons electronic configuration of atom atomic radius/pm electronic configuration of +1 ion ionic radius/pm lithium 3 2.1 152 2 68 sodium 11 2.8.1 185 98 potassium 19 2.8.8.1 227 133 (1 000 000 000 000pm = 1m) (a) Complete the table to show the electronic configuration in the ions of Group 1. [1] (b) (i) Describe and explain the trend in atomic radii down Group 1. [3] (ii) Describe and e xplain the change in the radius when a lithium atom form s a lithium ion. [2]

5 Setters: FKD/JK Chemistry Paper 2 [Turn Over (c) (i) The group 1 elements react with water vigorously. Write an equation to illustr