EJC Prelim P1

© EJC [Turn Over EUNOIA JUNIOR COLLEGE JC2 Preliminary Examination 2018 General Certificate of Education Advanced Level Higher 2 CHEMISTRY Paper 1 Multiple Choice 9729/01 24 September 2018 1 hour Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, civics group and registration number on the Answer Sheet in the spaces provided unless this has been done for you. 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 separate Answer Sheet. Read the instructions on the 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. This document consists of 12 printed pages.

2 © EJC 9729/01/J2PE/18 1 Following J. J. Thomson’s discovery of the electron in 1897, Ernest Rutherford devised the celebrated gold foil experiment, which led to a better understanding of the structure of the atom. In the experiment, a beam of heavy α particles, 42 2He + , was fired at a piece of thin gold foil as target. As expected, most of the α particles passed straight through the gold foil undeflected. However, some α particles are scattered, and a small number in fact deflected right back to the source. Which of the following conclusions cannot be drawn from the gold foil experiment? A Atom is mostly empty space. B Atom possesses a region of positive charge . C Electrons in atom orbit around a dense positively charged region. D The positive charge in an atom is concentrated within a very small volume. 2 The most common oxidation state of americium, Am, in aqueous solution is + n. Recently, Cu 3+ has been shown to quantitatively oxidise Am n+(aq) in dilute HNO 3 to the +2n oxidation state, while itself is reduced to Cu2+. In an experiment, 25.0 cm 3 of 0.0100 mol dm –3 Amn+(aq) was found to require 15.0 cm 3 of 0.0500 mol dm–3 Cu3+ for complete oxidation. What is the formula of the americium containing species formed? A Am 2+ B AmO 2 C 2AmO + D 2 2AmO + thin gold foil beam of α particles circular fluorescent screen source of α particles most α particles are undeflected some α particles are scattered

3 © EJC 9729/01/J2PE/18 [Turn Over 3 In which sequences are the molecules quoted in order of increasing bond angle around the central atom within the molecule? A OF 2 CH 4 SF 6 B H 2O O 3 N 2O C PF 3 BF 3 IF3 D NO 2 SO 2 CO 2 4 Unlike the reaction of ammonia with hydrogen chloride to give ammonium chloride, the reaction of ammonia with hydrogen fluoride produces colourless crystals o