2024 TMJC H2 Chem Prelim P1 (Ans)

___________________________________________________________________ H2 CHEMISTRY 9729/01 Paper 1 Multiple Choice 19 September 2024 1 hour Additional materials: Multiple Choice Answer Sheet Data Booklet _________________________________________________________________________ READ THESE INSTRUCTIONS FIRST Write in soft pencil. Write your name, class and register number 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 use of the Answer Sheet very carefully. You are advised to fill in the Answer Sheet as you go along . No additional time will be given for the transfer of answers once the examination has ended. 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. This document consists of 14 printed pages. Use of the Answer Sheet Ensure you have written your name, class register number and class on the Answer Sheet. Use a 2B pencil to shade your answers on the Answer Sheet; erase any mistakes cleanly. Multiple shaded answers to a question will not be accepted. For shading of class register number on the Answer Sheet, please follow the given examples: If your register number is 1, then shade 01 in the index number column. If your register number is 21, then shade 21 in the index number column. TAMPINES MERIDIAN JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATION

2 Tampines Meridian Junior College 2024 JC2 Preliminary Examination H2 Chemistry 1 Use of the Data Booklet is relevant to this question. A stream of gaseous Ca2+ 20 40 charged ions was passed through an electric field between two oppositely charged plates and the Ca2+ ions were deflected at an angle of +15.0°. Under the same electric field, a stream of unknown gaseous X3− ion was deflected at an angle of −29.0°. What is a possible atomic number of X? A 15 B 24 C 31 D 34 Answer: A angle of deflection q m ratio q m of Ca2+ 20 40 = 2 40 ➔ +15.0° q m of X3− = 3 Ar of X ➔ −29.0° 29 15 = 3 𝐴𝑟 𝑜𝑓 𝑋 2 40 Ar, mass of X = 31. 0 X could be phosphorus with 15 protons and 16 neutrons 2 Which statements correctly describe an electron shell with the principal quantum shell number n = 2? 1 A total of 10 electrons can be accommodated in this shell. 2 An orbital from this shell must be dumb-bell in shape. 3 The energy level of the orbitals in this shell is higher than that in n = 1. A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 3 only Answer: D Only 3 is correct An orbital in this shell may either be spherica