2024 ASRJC H2 Chem P2 (QP)

ASRJC JC2 PRELIM 2024 9729/02/H2 [Turn over ANDERSON SERANGOON JUNIOR COLLEGE 2024 JC 2 PRELIMINARY EXAMINATION NAME:______________________________ ( ) CLASS: 24 / _____ CHEMISTRY 9729/02 Paper 2 Structured Questions 11 September 2024 2 hours Candidates answer on the Question Paper. Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Write your name, class and register number 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. Answer all questions in the spaces provided on the Question Paper. The use of an approved scientific calculator is expected, where appropriate. A Data Booklet is provided. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Paper 2 1 /15 2 /13 3 /11 4 /16 5 /20 Total / 75 This document consists of 21 printed pages and 3 blank pages.

2 ASRJC JC2 PRELIM 2024 9729/02/H2 Answer all the questions. 1 (a) Phosphorus, sulfur and chlorine are Period 3 elements of the Periodic Table. Table 1.1 shows some properties of the three elements. Table 1.1 P S Cl number of electrons in 3p subshell number of unpaired electrons (i) Complete Table 1.1 to show the number of electrons in the 3p subshell and the number of unpaired electrons in an atom of P, S and Cl. [2] (ii) With reference to the Data Booklet, state and explain the trend of the ionic radius of P3–, S2– and Cl–. …………………………………………………………………………………………………... …………………………………………………………………………………………………... …………………………………………………………………………………………………... …………………………………………………………………………………………………... …………………………………………………………………………………………………... ……………………………………………………………………………………………….. [2] (b) Phosphoryl chloride, POCl3, is a colourless liquid that is used to make phosphate esters. P O Cl Cl Cl POCl3 has similar chemical properties as PC l5. It has a melting point of 1 °C and a boiling point of 106 °C. It also reacts vigorously with water, forming misty fumes and an acidic solution of H3PO4. (i) Explain how the information in (b) suggests that the structure and bonding of POCl3 is simple covalent. …………………………………………………………………………………………………... …………………………………………………………………………………………………... …………………………………………………………………………………………………... …………………………………………………………………………………………………... ……………………………………………………………………………………………….. [2]

3 ASRJC JC2 PRELIM 2024 9729/02/H2 [Turn over (ii) Write a balanced equation for the reaction of POCl3 with water. ……………………………………………………………………………………………….. [1] (iii) In H3PO4, there is no hydrogen atom directly bonded t