2024 Prelims VJC H2 Chem P1 (QP)

© VJC 2024 9729/01/PRELIM/24 [Turn over 1 VICTORIA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 2 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. Do not use staples, paper clips, glue or correction fluid. Write your index number, name and CT group on the Answer Sheet. There are thirty questions. 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. A Data Booklet is provided. 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. This document consists of 12 printed pages.

© VJC 2024 9729/01/PRELIM/24 2 For each question there are four possible answers, A, B, C, and D. Choose the one you consider to be correct. 1 Which arrangement of the four e lectrons of highest energy corresponds to the electronic configuration of a Group 14 element at its ground state? A 2s22p2 B 1s22s2 C 2s12p3 D 2s22p3 2 The table below shows the sixth ionisation energies of four consecutive elements in the Periodic Table. element W X Y Z sixth ionisation energy / kJ mol–1 19800 21300 8500 9360 What is the formula of the fluoride of W? A WF3 B WF4 C WF5 D WF6 3 Boron trifluoride, BF3, is very difficult to handle due to its high reactivity at room temperature. 1 mole of BF3 can react with 1 mole of dimethyl ether, CH3OCH3 to form compound J. Which statements are correct? 1 Lone pair electrons on oxygen in CH3OCH3 is donated to the vacant orbital of boron in BF3. 2 The bond angle around boron changes from 120 ° in BF 3 to 109.5 ° in compound J. 3 The molecular shape around oxygen changes from bent in CH 3OCH3 to trigonal planar in compound J. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 only 4 The boiling point of water (100°C) is greater than that of NH3 (–33.3°C). Which statement does not explain the relative boiling points of H2O and NH3? A The water molecule has a greater permanent dipole than the NH3 molecule. B Each hydrogen bond formed between water molecules is stronger than that formed between NH3 molecules. C There are, on average, more hydrogen bonds between water molecules than there are between NH3 molecules. D The O–H bonds in water are stronger than th