2021_VJC_Prelim_P2_Qns

1  VJC 2021 8873/02/PRELIM/21 [Turn over CANDIDAT E NAME CT GROUP VICTORIA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATIONS Higher 1 ……………………………………………….………….. …………………………….. CHEMISTRY 8873//02 Paper 2 Structured Questions Candidates answer on the Question Paper. 15 September 2021 2 hours Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Write your name and CT group on all the work you hand in. Write in dark blue or black pen. You may use a soft pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Section A Answer all the questions. Section B Answer one question. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Section A 1 / 8 2 / 13 3 / 9 4 / 9 5 / 13 6 / 8 Section B 7 / 8 / 20

2  VJC 2021 8873/02/PRELIM/21 [Turn over Total / 80 This document consists of 28 printed pages and 2 blank pages. Section A Answer all the questions in this section in the spaces provided. 1 (a ) The nth (n = 1, 2, 3, 4 or 5) ionisation energies of consecutive elements Q to Z, with atomic number below 20, are shown in Fig. 1.1. Fig. 1.1 (i) Define the nth ionisation energy of element T. …………………………………………………………………………………………….. . …………………………………………………………………………………………….. . …………………………………………………………………………………………….. . …………………………………………………………………………………………….. . [1] (ii) Element U is identified as Al. State the value of n. …………………………………………………………………………………………….. . [1]

3  VJC 2021 8873/02/PRELIM/21 [Turn over (b ) Aluminium chloride has a wide number of uses in the chemical industry. Anhydrous AlCl3 adopts different structures depending on the temperature and the state it is in. In the liquid state, it exists as the dimer Al2Cl6 while a mixture of monomer and dimer can be found in the gaseous phase. (i) State the type of interactions between two molecules of AlCl3. …………………………………………………………………………………………….. . [1] (ii) Draw a diagram to show the bonding in an Al2Cl6 dimer, and state the bond angle about the Al atom. …………………………………………………………………………………………….. . …………………………………………………………………………………………….. . [2] (c ) Beryllium chloride, BeCl2, has properties similar to those of AlCl3. (i) Explain why BeCl2 behaves similarly to AlCl3. …………………………………………………………………………………………….. . …………………………………………………………………………………………….. . …………………………………………………………………………………………….. . …………………………………………………………………………………………….. . [1] (ii) BeCl2 and dimeth