H1 Chem P2_SAJC_2024_QP

1 [TURN OVER ST ANDREW’S JUNIOR COLLEGE PRELIMINARY EXAMINATIONS HIGHER 1 CANDIDATE NAME CLASS 2 3 H1 CHEMISTRY 8873 / 02 Paper 2 Structured Questions 27 August 2024 2 hours Candidates answer on the Question Paper. Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Write your centre number, index number, name and class at the top of this page. Write in dark blue or black pen. You may use a HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Answer all questions in the spaces provided on the Question Paper. A Data Booklet is provided. Section A Answer all the questions. Section B Answer one question. The use of an approved scientific calculator is expected, where appropriate. The number of marks is given in brackets [ ] at the end of each question or part question. Question Number Total Marks Marks Obtained SECTION A 1 14 2 7 3 9 4 30 SECTION B 5 20 6 20 TOTAL 80 This document consists of 28 printed pages (including this cover page).

2 [TURN OVER Section A Answer all the questions in this section in the spaces provided. 1 This is a question about Group 14 elements and its compounds. (a) (i) A sample of silicon contains three isotopes, as shown in Table 1.1. Table 1.1 Isotope Relative Isotopic mass Percentage abundance. % 28Si 27.976 92.22 29Si 28.976 4.69 30Si 29.973 3.09 Calculate the relative atomic mass of silicon in this sample, giving your answer to two decimal places. [2] (ii) Complete the electronic configuration for silicon. [1] 1s2 ………………………………………………………………………………... (iii) Explain why second ionisation energy of silicon is lower than that of aluminium. [2] ……………………………………………………………………………………………... ……………………………………………………………………………………………... ……………………………………………………………………………………………... ……………………………………………………………………………………………...

3 [TURN OVER 1 (b) When carbon tetrachloride, CCl4, and silicon tetrachloride, SiCl4, were added to water, the following observations were seen. carbon tetrachloride Forms two immiscible layers silicon tetrachloride White solid and steamy fumes (i) Write a balanced equation for the reaction of SiCl4 with water. [1] ……………………………………………………………………………………………... (ii) CCl4 has no reaction with water. Suggest an explanation for the inertness of CCl4 to water. [1] ……………………………………………………………………………………………... ……………………………………………………………………………………………... (iii) Explain why CC l4 forms two immiscible layers with water when they are mixed. [2] ……………………………………………………………………………………………... ……………………………………………………………………………………………... ……………………………………………………………………………………………... ……………………………………………………………………………………………...

4 [TURN OVER 1 (c) Due to carbon’s ability to form strong multiple bonds, it can form different allotropes like graphene a