NYJC Prelim H1 Chem 8873 P1

[Turn Over This document consists of 15 printed pages. NANYANG JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 1 CHEMISTRY 8873/01 Paper 1 Multiple Choice 22 September 2025 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 H1 Chemistry 8873/01 NYJC J2/2025 PRELIM 1 X, Y and Z are different sub-atomic particles. X has a mass of 9.11 × 10−31 kg and Y has a mass of 1.67 × 10−27 kg. Z is not deflected when passed through an electric field. What could be the identities of X, Y and Z? X Y Z A electron neutron proton B electron proton neutron C proton electron neutron D proton neutron electron 2 M and T are cations. M contains n protons and has a charge of 3+. T contains (n –2) protons and has the same number of electrons as M. What is the formula of the oxide formed by T? A TO B T2O C T2O3 D TO2 3 When aqueous copper(II) sulfate is mixed with potassium iodide, a white precipitate of CuI in a brown solution is formed. What is the electronic configuration of the copper cation in the white precipitate? A 1s2 2s2 2p6 3s2 3p6 3d9 B 1s2 2s2 2p6 3s2 3p6 3d7 4s2 C 1s2 2s2 2p6 3s2 3p6 3d10 D 1s2 2s2 2p6 3s2 3p6 3d9 4s1

3 H1 Chemistry 8873/01 NYJC J2/2025 PRELIM [Turn Over 4 The boiling point of methane is −161.5 oC while that of neon is −264 oC. Why is the boiling point of methane greater than that of neon? A Molecules of methane have a larger surface area to form stronger intermolecular forces than those of neon. B A molecule of methane has more electrons than an atom of neon. C A molecule of methane has a greater relative molecular mass than an atom of neon. D Molecules of methane form hydrogen bonds, but those of neon do not. 5 Boron trifluoride is a highly reactive gas at room temperature and hence it is difficult to handle. To store it in liquid form, 2 mol of BF 3 reacts with 1 mol of CH 3CH2OCH2CH3 to form compound N. Which statement is correct? A The boron atom in compound N has an incomplete octet. B 2 mol of AlF3 can also react with 1 mol of CH3CH2OCH2CH3 to form a similar compound. C Two dative bonds are formed from the boron atom in two BF 3 molecules towards the O atom in CH3CH2OCH2CH3. D The bond angle with respect to boron atom in BF 3 is bigger than the bond angle with respect to boron in compound N.

4 H1 Chemistry 8873/01 NYJC J2/2025 PRELIM 6 Which pairs of ions give an ionic compound with the lowest melting point? cation anion A P CH3 CH3 CH3 CH3 S O O O O B P CH2CH3 CH3CH2 CH2CH3 CH2CH3 S O O CH3 O C P CH3 CH3 CH3 CH3 S O O CH3 O D P CH2CH3 CH3CH2 CH2CH3 CH2CH3 S O O O O 7 X is a transition element that forms ions of various oxidation states. One ion, X 2+, reduces Cr2O72− in acid solution. If 1 mol of Cr2O72− is reduced by 2 mol of X2+, which species is formed in the reaction? A XO42− B XO2+ C XO2+ D X3+ 8 Use of the Data Booklet is relevant to this question. Osmium, 76Os, is an exceptionally dense metal, with a density of 23 g cm−3. How many atoms are present in 1.0 cm3 of Os? A 7.3 x 1022 B 1.8 x 1023 C 2.0 x 1024 D 5.0 x 1024

5 H1 Chemistry 8873/01 NYJC J2/2025 PRELIM [Turn Over 9 Sodium azide, NaN 3, and potassium nitrate, KNO 3, are both present in the airbags of some cars. When the airbag is activated, the sodium azide first decomposes to give sodium and nitrogen. 2NaN3(s) → 2Na(s) + 3N2(g) The sodium then reacts with the potassium nitrate to produce more nitrogen. 10Na(s) + 2KNO3(s) → K2O(s) + 5Na2O(s) + N2(g) The nitrogen produced in these two reactions inflates the airbag. The amount of gas needed to inflate the airbag is 2.00 mol. Which amount of sodium azide is needed to make a total of 2.00 mol of nitrogen gas? A 0.625 mol B 1.00 mol C 1.25 mol D 1.33 mol 10 Use of the Data Booklet is relevant to this question. Due to its radioactive nature, the properties of astatine, At, have to be predicted based on its position in the Periodic Table. Which statement concerning At or its compounds is correct? A Hydrogen astatide has a higher decomposition temperature than hydrogen bromide. B Astatine is a light coloured solid at room temperature. C Silver astatide is soluble in NH3(aq). D Astatine is a weaker oxidising agent than iodine.

6 H1 Chemistry 8873/01 NYJC J2/2025 PRELIM 11 The graph below shows the variation in the boiling point for 8 consecutive elements in the Periodic Table, all with atomic number less than 21. Which statements are correct? 1 The chloride of E reacts with aqueous sodium hydroxide to give a precipitate which is soluble in excess sodium hydroxide. 2 The oxide of F is neutral in aqueous solution. 3 The oxide of K dissolves readily in water to give a strongly alkaline solution. A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 1 only 12 The variation in the melting points of the elements in Period 3 can be explained by reference to their structure and bonding. Which row is correct? relative melting point of two elements explanation A Al > Na aluminium is giant covalent, sodium is giant metallic B Cl > S chlorine has stronger instantaneous dipole-induced dipole forces due to the additional electron in each chlorine atom C Mg > Cl magnesium is giant metallic, chlorine is simple molecular D Si > P both are giant covalent but the bonding in silicon is stronger E K G F boiling point H I J L atomic number

7 H1 Chemistry 8873/01 NYJC J2/2025 PRELIM [Turn Over 13 In which reaction is the underlined substance in the equation acting as a Bronsted-Lowry base? A CaO(s) + H2O(l) → Ca(OH)2(aq) B CH3CH2Cl(g) + OH−(aq) → CH3CH2OH(aq) + Cl−(aq) C NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l) D NH3(g) + HCl(g) → NH4Cl(s) 14 Use of the Data Booklet is relevant to this question. At 60 °C the ionic product of water, Kw, has the value of 9.5 x 10−14 mol2 dm−6. Which statements concerning water at 60 °C are correct? 1 [OH−] = 4.75 x 10−7 mol dm−3 2 heating water from 25 °C to 60 °C causes water to ionise more 3 the pH is 6.51 A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 1 only 15 Acid Q is a strong acid. A 0.050 mol dm−3 solution of Q has a pH of 1.00. Which acid is Q? A HCl B HNO3 C H3PO4 D H2SO4

8 H1 Chemistry 8873/01 NYJC J2/2025 PRELIM 16 The rate of a reaction is measured in mol dm−3 s−1. Which row is correct? overall order of reaction units of rate constant A zero mol−1 dm−3 s−1 B first mol dm3 s−1 C second mol2 dm−6 s−1 D third mol−2 dm6 s−1 17 The gaseous decomposition reaction of X is observed to be first order. X(g) → 2Y(g) + Z(g) In an experiment, 0.10 mol of pure X(g) was put into an evacuated flask. It was found that there was 0.025 mol of X left after 30 minutes. Which statements are correct? 1 There was 0.0625 mol of X left after 15 minutes. 2 There was 0.05 mol of Z in the flask after 30 minutes. 3 It took 15 minutes for the am