HCI Prelim P1_QP

This document consists of 12 printed pages. HWA CHONG INSTITUTION C2 Preliminary Examinations Higher 2 CANDIDATE NAME CT GROUP 16S CENTRE NUMBER INDEX NUMBER CHEMISTRY Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet Data Booklet 9729/01 20 September 2017 1 hour READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Complete the information on the Answer Sheet as shown below. There are 30 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 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.

© Hwa Chong Institution 2017 9729 / 01 / C2 Prelim 2017 2 1 Why is the second ionisation energy of sodium higher than that of magnesium? A Magnesium has more protons than sodium. B Sodium has a complete octet, but magnesium does not. C The ionic radius of Na+ ion is larger than that of Mg+ ion. D The electron to be removed from sodium is closer to the nucleus. 2 Use of the Data Booklet is relevant to this question. A mass of 0.457 g of solid carbon dioxide was vapourised into an evacuated gas syringe at r.t.p. A small amount of inert gas was introduced into the gas syringe and the volume of the gas syringe was 334.5 cm3. The temperature was kept constant throughout. How much inert gas was introduced into the gas syringe? A 1.4  10–2 mol B 3.3  10–3 mol C 3.5  10–3 mol D 4.3  10–3 mol 3 Propadiene and propyne both have the same molecular formula, C 3H4. They exist in equilibrium as shown: H2C=C=CH2 ⇌ CH3CCH propadiene propyne Which bond is present in propadiene but not present in propyne? A a  bond formed by 1s – 2sp overlap B a  bond formed by 2p – 2p overlap C a  bond formed by 2sp – 2sp2 overlap D a  bond formed by 2sp2 – 2sp2 overlap

© Hwa Chong Institution 2017 9729 / 01 / C2 Prelim 2017 3 4 Which molecules contain a 90º bond angle? 1 SF6 2 PCl5 3 XeF4 4 SiCl4 A 1, 2, 3 and 4 B 1, 2 and 3 only C 1 and 2 only D 3 and 4 only 5 When T l+(aq) ions are reacted with VO 3–(aq) ions, T l3+(aq) ions and V 2+(aq) ions are formed. Assuming the reaction goes to completion, how many moles of Tl+(aq) and VO3–(aq) would result in a mixture containing equal number of moles of VO 3–(aq) and V 2+(aq) once the reaction had taken place? moles of Tl+(aq) moles of VO3–(aq) A 1 2 B 1 3 C 3 2 D 3 4 6 Compound G is produced by actinobacteria in the soil and is responsible for the “it just rained” smell. How many moles of oxygen gas are needed