2024 H1 Prelim Paper 1 HCI

This document consists of 9 printed pages and 1 blank page. © Hwa Chong Institution 8873/01/Prelim 2024 [Turn over HWA CHONG INSTITUTION C2 Preliminary Examination Higher 1 CANDIDATE NAME CT GROUP 23S CENTRE NUMBER INDEX NUMBER CHEMISTRY Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet Data Booklet 8873/01 16 September 2024 1 hour READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid or tape. Write your name and CT group in the space provided at the top of this page. Complete the information on the Answer Sheet as shown below. There are thirty 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 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 © Hwa Chong Institution 8873/01/Prelim 2024 [Turn over 1 Use of the Data Booklet is relevant to this question. Which species has one unpaired electron? A Li+ B P C Cl D Cu+ 2 Use of the Data Booklet is relevant to this question. The mineral pyrite contains sulfur and iron. A sample of pyrite was analysed and four different types of atom were identified; V, W, X and Y. Table 1.1 shows information about the four types of atom found in the sample. Table 1.1 Atom relative mass relative % abundance V 31.97 63.8 W 33.97 2.8 X 53.94 31.4 Y 55.95 2.0 What is the relative atomic mass of sulfur in this sample? A 21.35 B 32.05 C 39.04 D 54.06 3 A substance, Z, has the following properties. • melting point –39 °C • boiling point 357 °C • insoluble in water • conducts electricity when solid and when molten What is the structure of Z? A giant molecular B ionic C metallic D simple molecular 4 What happens as ice melts at 0°C? 1 Molecules gain kinetic energy and temperature increases. 2 Energy is gained to overcome the hydrogen bonds between molecules. 3 Molecules gain sufficient energy to move from fixed positions. A 1 only B 1 and 2 only C 1 and 3 only D 2 and 3 only

3 © Hwa Chong Institution 8873/01/Prelim 2024 [Turn over 5 Which compound has the highest boiling point? A CH3CH2F B CH3CH2OH C CH3CHO D CH3OCH3 6 Ethene is the monomer of the polymer, poly(ethene). How do the carbon-carbon bond length and the H–C–H bond angle in ethene compare with that in poly(ethene)? carbon-carbon bond length is H–C–H bond angle is A longer in ethene larger in ethene B longer in ethene smaller in ethene C shorter in ethene larger in ethene D shorter in ethene smaller in ethene 7 Use of the Data Booklet is relevant to this question. Which diagram shows the correct trends when the melting points of the elements Mg, Al, Si and P are plotted against their first ionisation energies? A B C D melting point first ionisation energy melting point first ionisation energy  Al  P  Si  Mg  Mg  P  Si  Al melting point first ionisation energy melting point first ionisation energy  Mg  P  Si  Al  Al  P  Si  Mg

4 © Hwa Chong Institution 8873/01/Prelim 2024 [Turn over 8 Which method can be used to distinguish HCl(aq) and HCO2H(aq) of equal concentrations? A measuring the electrical conductivity of 20 cm3 of each solution. B measuring the total mass loss when reacting with 1.0 g of K2CO3(s) C measuring the volume of NaOH(aq) needed to neutralise 20 cm3 of each solution. D measuring the total volume of gas produced when reacting with 2.0 g of Mg ribbon. 9 Which two species act as Bronsted-Lowry acids in the reaction? H2PO4−(aq) + OH−(aq) HPO42−(aq) + H2O(l) A HPO42−(aq) and OH−(aq) B H2PO4−(aq) and HPO42−(aq) C HPO42−(aq) and H2O(l) D H2PO4−(aq) and H2O(l) 10 The dissociation of water is given as: H2O(l) H+(aq) + OH−(aq) ΔH = +57 kJ mol−1 Kw is the ionic product of water. What happens to the values of Kw and [H+] if the temperature of water is increased? Kw [H+] A increase decrease B increase increase C decrease decrease D decrease increase 11 Which oxide produces an aqueous solution with the highest pH? A Na2O B MgO C SiO2 D P4O10 12 Which property increases down the group for Group 1 (Na to Cs)? A charge density of the cation B reactivity of the element with water C magnitude of lattice energies of the oxides D melting point of the elements

5 © Hwa Chong Institution 8873/01/Prelim 2024 [Turn over 13 Which statement about the properties of phosphorus or its compounds is incorrect? A The oxide of phosphorus reacts with water to give an acidic solution. B Phosphorus exist as simple molecules in its elemental state. C Phosphorus is the only element in Period 3 whose chloride reacts with water to form HCl. D Phosphorus has the highest first ionisation energy compared to its adjacent elements within the same period. 14 Which statement is correct? A One mole of a compound is the amount that contains the same number of atoms as there are atoms in 12.000 g of carbon-12. B The relative isotopic mass of lithium-7 is given by the following expression. average mass of all isotopes of lithium 1 12 the mass of one atom of carbon-12 C The relative atomic mass of oxygen is given by the following expression. average mass of one atom of oxygen 1 12 the mass of one atom of carbon-12 D The relative molecular mass of a compound E is given by the following expression. average mass of one atom of E 1 12 the mass of one atom of carbon-12 15 Use of the Data Booklet is relevant to this question. Which of the following has the value of 6.02 x 1023 in 32.0 g of methanol? 1 the number of methanol molecules 2 the number of oxygen atoms 3 the number of hydrogen atoms A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3 16 Lead reacts with nitrate ions in the redox reaction below. …… Pb (s) + …… NO3− (aq) + …… H+ (aq) → …… NO (g) + …… Pb2+ (aq) + …… H2O (l) What is the coefficient for H+ in the correctly balanced equation? A 2 B 4 C 6 D 8

6 © Hwa Chong Institution 8873/01/Prelim 2024 [Turn over 17 Which statement is correct? A In an exothermic reaction, the products have more energy than the reactants. B In an exothermic reversible reaction, the activation energy of the forward reaction is greater than that of the reverse reaction. C In an endothermic reaction, the products are more stable than the reactants. D In an endothermic reversible reaction, the activation energy of the forward reaction is greater than that of the reverse reaction. 18 Which change is exothermic? A Cl2(g) → 2Cl(g) B H2O(g) → H2O(l) C K(g) → K+(g) + e− D KCl(s) → K+(g) + Cl−(g) 19 The initial rate of a reaction can be determined from concentration-time graphs. What is the value of the initial rate of the reaction as determined from the graph below? A 0.1 B 1.0 C 1.6 D 10 Concentration of reactant (mol dm−3)

7 © Hwa Chong Institution 8873/01/Prelim 2024 [Turn over 20 What are the correct axes labels for a Maxwell-