Compassvale Sec 4Exp Prelim Chem P2 2024 QP

COMPASSVALE SECONDARY SCHOOL Secondary Four Express Preliminary Examination 2024 NAME CENTRE NUMBER S CLASS INDEX NUMBER ___________________________________________________________________________ CHEMISTRY 6092/02 Paper 2 23 August 2024 1 hour 45 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your Centre number, class, index number and name on all the work you hand in. Write in dark blue or black pen. 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. Write your answers in the spaces provided. Section B Answer one question. Write your answers 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 21. The use of an approved scientific calculator is expected, where appropriate. __________________________________________________________________________ This document consists of 21 printed pages and 1 blank page. Set by: Ms Tay SW [Turn over

2 Section A Answer all questions. 1 (a) A list of symbols and formulae is shown. Al3+ Ar CH4 CO2 Cl2 Fe3+ H2 O2 O2‒ NO NO2 Zn2+ Answer the following questions about these symbols and formulae. Each symbol or formula may be used once, more than once or not at all. Which symbol or formula represents: (i) a compound which contributes to global warming, ……………………………………………………………………………………………........ [1] (ii) a compound which is taken in by plants during photosynthesis, ……………………………………………………………………………………………........ [1] (iii) a gas which comprises 0.93% of clean dry air, ………………………………………………………………….………………….………...... [1] (iv) a gas which bleaches damp litmus paper, ………………………………………………………………….………………….………...... [1] (v) an ion which forms a white precipitate that is insoluble in excess aqueous ammonia, ………………………………………………………………….……………………….…...... [1] (vi) an ion formed when an atom gains electrons? ………………………………………………………………….…………………………....... [1]

3 (b) Oxides of non-metals can be classified as acidic or neutral. Give an example of each and explain its classification. acidic oxide …………………………………………………………………………………….........