NYJC 2022 Prelim P1

[Turn Over This document consists of 22 printed pages. NANYANG JUNIOR COLLEGE JC 2 Preliminary Examination Higher 2 CHEMISTRY 9729/01 Paper 1 Multiple Choice 20 Sep 2022 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, CT and NRIC / FIN on the Answer Sheet in the spaces provided. There are thirty questions in 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 booklet. The use of an approved scientific calculator is expected, where appropriate.

2 H2 Chemistry 9729/01 NYJC J2/2022 PXver 1 Use of the Data Booklet is relevant to this question. Outside the city of Wuwei in China, there is an experimental nuclear reactor that has the potential to generate much smaller amounts of radioactive wastes compared to conventional reactors. In this reactor, isotopes of thorium-232 are irradiated with neutrons to produce isotope Q, which then decompose to form isotope R, and finally to uranium-233 in a three-step radioactive decay reaction shown below. Q RTh 232 90 U 233 92+ n 1 0 Which row describes: • the identity of the element of isotope Q, • the neutron number of isotope R? Q neutron number of R A protactinium 142 B protactinium 141 C thorium 142 D thorium 141 2 Use of the Data Booklet is relevant to this question. Which element has the highest 3rd ionisation energy? A Cd B Rb C Sr D Xe

3 H2 Chemistry 9729/01 NYJC J2/2022 PX [Turn Over 3 Gallium, atomic number 31, is a silvery blue lustrous solid. It has a low melting point of 29.8 °C, becoming silvery white in the liquid state. Analysis of the crystal structure of gallium shows the existence of only covalent Ga2 dimers. Unlike its melting point, gallium has a high boiling point of 2400 °C, similar to other Group 13 elements such as aluminium and indium. Ga2 dimers are not present in liquid gallium. Which statements explain the observed melting and boiling points of Gallium? 1 In the liquid state, gallium exist as cations surrounded by a sea of delocalised valence electrons. 2 In the solid state, there are weak instantaneous dipole -induced dipole interactions between Ga2 dimers. 3 In the solid state, there are strong covalent bonds between Ga atoms. A 1, 2 and 3 B 1 and 2 C 2 and 3 D 1 only 4 At sea level, an inflated bicycle tyre has an internal pressure of 6.8 bar and a temperature of 30 °C. The instructions on the tyre state ‘Safety note: internal press