NYJC 2022 Prelim P2

[Turn over NANYANG JUNIOR COLLEGE JC 2 PRELIMARY EXAMINATION Higher 2 CANDIDATE NAME CLASS TUTOR’S NAME CHEMISTRY 9729/02 Paper 2 Structured 12 September 2022 2 hours Candidates answer on the Question Paper Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Write your name and class on all the work you hand in. Write in dark blue or black pen on both sides of the paper. You may use a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. Answer all questions in the spaces provided. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use 1 /15 2 /10 3 /6 4 /24 5 /8 6 /12 Total /75 This document consists of 20 printed pages.

2 H2 Chemistry 9729/02 NYJC J2/22 PX [Turn Over For Examiner's Use Answer all questions in the spaces provided. 1(a) X and Y are oxides of elements in the third period of the Periodic Table. The oxidation number of the Period 3 element in X and Y is +3 and +5 respectively. X reacts with both aqueous sodium hydroxide and aqueous hydrochloric acid. Y reacts with aqueous sodium hydroxide, but not with aqueous hydrochloric acid. (i) Identify the formulae of X and Y. X ................................ ........................... Y ................................ ..................... [1] (ii) Write equations for the reactions of X and Y with aqueous sodium hydroxide. X: ................................ ................................ ................................ ............................ Y: ................................ ................................ ................................ ........................ [2] (b) The graph below shows the boiling points of HCl, HBr and HI. (i) Explain the trend of the boiling points of HCl, HBr and HI. ......................................................................................................................... ......................................................................................................................... ......................................................................................................................... ......................................................................................................................... ......................................................................................................................... .........................................................................