2024 H1 Chem Prelim P1 QP VJC

© VJC 2024 8873/01/PRELIM/24 [Turn over 1 VICTORIA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 1 CHEMISTRY 8873/01 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 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 10 printed pages and 2 blank pages.

© VJC 2024 8873/01/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 Use of Data Booklet is relevant to this question. Which particle has a half-filled set of p orbitals? A C– B N2– C F+ D Ne 2 The table 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 Q. 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 about boron changes from 120 ° in BF3 to 107° in compound Q. 3 The molecular shape about oxygen changes from bent in CH3OCH3 to trigonal pyramidal in compound Q. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only 4 In which of the following pairs does the second molecule have a greater net dipole moment than that of the first molecule? A NH3, CCl4 B CO, HF C H2O, H2S D CO2, BF3

© VJC 2024 8873/01/PRELIM/24 [Turn over 3 5 Consider the following three compounds. 1 (CH3)2CHOH 2 CH3CH2CHO 3 CH3CH2CH2OH What is the order of decreasing boiling points of the compounds? A 1, 3, 2 B 2, 1, 3 C 3, 2, 1 D 3, 1, 2 6 In which reactions is the first reactant acting as a Bronsted-Lowry base? 1 NH3 + CH3Cl → CH3NH2 + HCl 2 HNO3 + H2SO4 → H2NO3+ + HSO4– 3 H2O + HNO3 → H3O+ + NO3– A 1, 2 and 3 B 1 and 3 only C 2 and 3 only D 2 only 7 The ionic product of water, Kw, is found to increase when the temperature of water is raised. Which statement describes what happens when the temperature of water is raised? A pH of water decreases and [H+] = [OH–] B pH of water decreases and [H+] is greater than [OH–] C pH of water increases and [H+] is less than [OH–] D pH of water increases and [H+] = [OH–] 8 10.0 cm 3 of 0.010 mol dm–3 solution of nitric acid is diluted with deionised water to form 100 cm3 of solution. What is the pH of the resulting solution? A 1 B 2 C 3 D 4

© VJC 2024 8873/01/PRELIM/24 4 9 The following titration curve shows the changes in pH of 25.0 cm 3 of 0.125 mol dm ‒3 monoprotic base (solution B) when an excess monobasic acid (solution A) is added to it gradually. Which statement about this titration is correct? A Solution B contains a strong base. B Solution A contains a weak acid. C The concentration of solution A used in the titration is 0.500 mol dm–3. D Bromocresol green (pH range 3.8 – 5.4) is a suitable indicator to detect the endpoint of this titration. 10 Which statement is incorrect about the following equilibrium that is present in blood? H2CO3(aq) ⇌ H+(aq) + HCO3–(aq) A pH of blood will remain relatively constant when there is a large amount of H+ added. B A decrease of [H+] in blood will cause more hydrogencarbonate ions to be formed. C A solution containing a large reservoir of H2CO3 and HCO3– is a buffer. D It is present in blood to control its pH. 11 Which of the following is correct about sodium to sulfur in the Period 3 of the Periodic Table? A The oxides formed by these elements become more ionic across the period. B Phosphorus is the only element in this period which forms more than one oxide. C The chlorides formed by these elements become more covalent across the period. D The chloride formed by sodium can dissolve in water to give a solution that will turn blue litmus red. Volume of A added / cm3 pH 0 12.50 0 11.10 5.22

© VJC 2024 8873/01/PRELIM/24 [Turn over 5 12 Which statements about the Group 1 elements, sodium, potassium, rubidium and caesium are correct? 1 Rubidium reacts with water more easily than sodium. 2 Potassium loses electrons less easily than caesium. 3 Caesium is a more powerful oxidising agent than rubidium. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only 13 Singaporium, 117Sg, is a hypothetical element in Group 17 of the Periodic Table below iodine. What is likely to be incorrect for Singaporium? A Singaporium is a solid at room temperature and pressure. B The bond energy of Sg–Sg is less endothermic than that of I–I. C Sg2 is unable to oxidise iodide to iodine. D HSg is unable to decompose to H2 and Sg2 when heated with a red-hot steel. 14 An organic molecule has • three elements; • the composition by mass, C, 54.5%; H, 9.1% What could this molecule be? 1 CH3CH2CH2CO2H 2 CH2(CHO)CH2CH2OH 3 CH3CH=CHCH2SH A 1, 2 and 3 B 1 and 3 only C 2 and 3 only D 2 only 15 In acidic solution, dichromate(VI) ions oxidise hydrogen peroxide, H2O2. In alakline solution, hydrogen peroxide oxidises chromium(III) ions. Which conditions of oxidation produce oxygen gas? A both acid and alkaline oxidations B neither acid nor alkaline oxidation C only the acid oxidation D only the alkaline oxidation

© VJC 2024 8873/01/PRELIM/24 6 16 Use of the Data Booklet is relevant to this question. KCN is used to extract gold, Au, from its ore. Gold dissolves in an aqueous cyanide solution in the presence of air to form Au(CN)2–, which is stable in aqueous solution. 4Au(s) + 8CN–(aq) + O2(g) + 2H2O(l) → 4Au(CN)2–(aq) + 4OH–(aq) What is the minimum volume of air, measured at room temperature and pressure, needed to extract 10 kg of gold from its ore? [You may assume the oxygen content in air to be 20%.] A 305 dm3 B 610 dm3 C 1520 dm3 D 3050 dm3 17 Which reactions represent the enthalpy change of formation of a substance? 1 Li+(g) + Cl–(g) → LiCl(s) 2 2H2(g) + O2(g) → 2H2O(l) 3 Na(s) + 1 2 Cl2(g) → NaCl(s) A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 3 only 18 The diagram illustrates the energy changes of a set of reactions occurring at stand