SJI 2024 Y4 Prelim Chemistry Paper 2

ST. JOSEPH’S INSTITUTION PRELIMINARY EXAMINATION 2024 (YEAR 4) CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY Paper 2 Candidates answer on the Question Paper. No Additional Materials are required. 6092/02 14 August 2024 1 hour 45 minutes (11:50 – 13:35) READ THESE INSTRUCTIONS FIRST Write your name, class and index number on all the work you hand in. Write in dark blue or black fluid ink pen. You may use a soft pencil for any diagrams, graphs or rough working. 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. The use of an approved scientific calculator is expected, where appropriate. A copy of the Periodic Table is printed on page 2. For Examiner’s Use Section A / 70 Section B / 10 Total / 80 This document consists of 26 printed pages.

2

3 Section A Answer all questions. 1 Select elements from the list to answer the following questions. You may use each element once, more than once or not at all. argon iodine neon chlorine iron sodium hydrogen lithium zinc (a) Which element shows both metallic and non-metallic character? ……………….…………………………………………………………………………..[ 1] (b) Which element, other than iron, is used in the manufacture of steel? ……………….…………………………………………………………………………..[1] (c) Which element gives a reddish-brown solution when added to aqueous potassium bromide? ……………….…………………………………………………………………………..[1] (d) Which two elements react together most vigorously? ……………….…………………………………………………………………………..[1] (e) (i) Which elements, when separately added to aqueous copper( II) nitrate, will cause a gas to be formed? ………………..……………………................................................................[ 1] (ii) For one of the elements in (e)(i), write a chemical equation for the formation of the gas. ………………..……………………................................................................[ 1] [Total: 6]

4 2 (a) A reaction in which the same element is both oxidised and reduced is called a disproportionation reaction. The reaction between chlorine and hydroxide ions is shown below. 3Cl2 + 6OH- → 5Cl- + ClO3- + 3H2O Use oxidation states to explain why this reaction is a disproportionation reaction. ..………………..…………………………………………………………………………… ..………………..…………………………………………………………………………… ..………………..…………………………………………………………………………… ……………….…………………………………………………………………………..[2] (b) 1.0 g samples of two oxochlorides, Si2OCl6 and Si3O2Cl