VJC 2021 Prelim H2P3 Qns [Final]

1 Ó VJC 2021 9729/03/PRELIM/21 [Turn over CANDIDATE NAME CT GROUP VICTORIA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATIONS Higher 2 ……………………………………………….………….. …………………………….. CHEMISTRY 9729//03 Paper 3 Free Response Candidates answer on the Question Paper. 20 September 2021 2 hours Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Write your index number, name and CT group in the spaces 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. If additional space is required, you should use the pages at the end of this booklet. The question number must be clearly shown. Section A Answer all questions. Section B Answer one question. A Data Booklet is provided. 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. For Examiner’s Use 1 /21 2 /17 3 /22 4 or 5 /20 Total /80 This document consists of 34 printed pages and 2 blank pages.

2 Ó VJC 2021 9729/03/PRELIM/21 [Turn over Section A Answer all the questions in this section. 1 (a) Elements in the same group tend to form products with similar physical properties. However, the oxides of carbon and silicon have very different physical structures. While CO2 exists as a gas at room temperature, SiO2 is a solid. (i) Explain, in terms of structure and bonding, the difference in the physical states of CO2 and SiO2. [2] (ii) Describe the bonding in a single CO2 molecule. Include a fully labelled diagram showing how the different types of bonds are formed in terms of orbital overlap. [2] (iii) By considering the extent of overlap of the orbitals, suggest a reason why SiO2 does not form bonds similar to that of CO2. [1] ………………………………………………………………………………………………. ………………………………………………………………………………………………. ………………………………………………………………………………………………. ………………………………………………………………………………………………. ………………………………………………………………………………………………. ………………………………………………………………………………………………. ………………………………………………………………………………………………. ………………………………………………………………………………………………. ………………………………………………………………………………………………. ………………………………………………………………………………………………. ………………………………………………………………………………………………. ………………………………………………………………………………………………. ………………………………………………………………………………………………. ………………………………………………………………………………………………. ………………………………………………………………………………………………. ………………………………………………………………………………………………. ………………………………………………………………………………………………. ……………………………………………………………………………………………….

3 Ó VJC 2021 9729/03/PRELIM/