2020 MI Prelim Paper 1_answer

Class Adm No Candidate Name: This question paper consists of 12 printed pages and 2 blank pages. 2020 Preliminary Examination Pre-University 3 H2 CHEMISTRY 9729/01 Paper 1 Multiple Choice 22 Sep 2020 1h Additional materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Do not turn over this question paper until you are told to do so Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, class and admission number in the spaces provided at the top of this page and on the Multiple Choice Answer Sheet provided. There are thirty questions on this paper. Answer ALL questions. For each question there are four possible answers A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the Multiple Choice Answer Sheet provided. Read the instructions on the Multiple Choice Answer Sheet very carefully. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done in this question paper. The use of an approved scientific calculator is expected, where appropriate. FOR EXAMINER’S USE TOTAL (30 marks)

2 For each question there are four possible answers, A, B, C, and D. Choose the one you consider to be correct. 1 Which statement about a 36.0 g sample of 18O2 is correct? A There are 6.02 × 1023 18O atoms in the sample. B The number of atoms is the same as the number of atoms in a 32.0 g sample of 16O2. C The number of moles in the sample is the same as the number of moles in a 40.0 g sample of H218O. D The number of molecules is the same as the number of atoms in a 20.0 g sample of H218O. 2 In gold mining, potassium c yanide is used to dissolve gold in order for easier extraction. The equation, commonly known as the Elsner equation, is given below. 4 Au + 8 KCN + O2 + 2H2O ⟶ 4 K[Au(CN)2] + 4 KOH What is the minimum volume of oxygen required to dissolve 1 kg of gold, assuming room temperature and pressure? A 28.8 dm3 B 30.5 dm3 C 461 dm3 D 487 dm3 3 Which of the following experiences the greatest deflection in the same electric field? A 3H+ B 9F- C 12Mg2+ D 32S2- 4 Which of the following pairs have the same molecular shape? A BCl3 and ICl3 B HCN and H2O C CF4 and SF4 D SCl2 and H2S

3 [Turn over 5 Which of the following pairs contains a compound held together by permanent dipole-permanent dipole interactions and a compound containing ionic bonds? A ClO2, AlCl3 B HCl, AlCl3 C NH4Cl, NaCl D HCl, NaCl 6 Which of the following molecules will not form hydrogen bonds with another of its own molecule? A CH3OCH3 B CH3COOH C (CH3)3CNH2 D (CH3)2CHOH 7 To determine the enthalpy change of