2025 JC2 Prelims H2 Chem Paper 1 QP_TJC

1 9729 / TJC Prelims / 2025 TEMASEK JUNIOR COLLEGE 2025 JC2 PRELIMINARY EXAMINATION Higher 2 CHEMISTRY 9729/01 Paper 1 Multiple Choice 17 September 2025 1 hour Additional Materials: Multiple Choice Answer Sheet (OMS) Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. There are thirty questions In this paper. Answer all questions. For each question there are four possible answers A, B, C, 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. Write your name & Civics Group on the Answer sheet. Shade your index number in the appropriate boxes. 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 16 printed pages.

2 9729 / TJC Prelims / 2025 1 Which ion would undergo the greatest deflection in an electric field? A 4He2+ B 19F− C 14N2+ D 16O22+ 2 An isolated gaseous species has paired electrons in at least one of its 3d orbitals and a fully filled 4s subshell. What could be the identity of the species? A Cu B Mn C Fe D Fe2+ 3 Which of the following cannot be explained by hydrogen bonding? A The existence of the hydrogen-difluoride anion, HF2–. B The difference in volatility between pentan-1-ol and hexan-1-ol. C The difference in melting point between 2-nitrophenol and 4-nitrophenol. D The higher than expected relative molecular mass of ethanoic acid in benzene. 4 Four substances have the physical properties shown. Which substance exists as a simple molecular solid at room temperature? melting point / C electrical conductivity solubility in water A −7 does not conduct slightly soluble B 46 does not conduct insoluble C 420 conducts insoluble D 782 does not conduct soluble

3 9729 / TJC Prelims / 2025 [Turn over 5 Which species contain dative (co-ordinate) bonding? 1 CO 2 N2H4 3 N2O4 A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 3 only 6 10 cm 3 of a hydrocarbon was mixed with 50 cm 3 of oxygen and combusted completely. After the resulting gas mixture was cooled and passed through aqueous sodium hydroxide, the volume of the residual gas mixture was found to be ¼ the volume of the original gas mixture before combustion. All volumes were measured at room temperature and pressure. What is the formula of the hydrocarbon? A C2H4 B C2H6 C C3H6 D C3H8 7 Which species contains a different number of electrons from the other three? A ClO4– B H2SO4 C SO42– D Sn2+

4 9729 / TJC Prelims / 2025 8 Group 2 carbonates such as calcium carbonate decompose thermally to give the metal oxide and carbon