MI 2022 PU1 H2 CHEM EOY

Class Adm No Candidate Name: This question paper consists of 17 printed pages and 1 blank page. 2022 End-of-Year Examination Pre-University 1 H2 CHEMISTRY 9729/01 Paper 1 Multiple Choice & Structured Questions 12 Oct 2022 2 hours Additional materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Do not turn over this question paper until you are told to do so Write your name, class and admission number on all the work you hand in. For Section A, there are fifteen 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 Multiple Choice Answer Sheet provided. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Read the instructions on the Multiple Choice Answer Sheet very carefully. For Section B, write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Answer all the questions. The use of an approved scientific calculator is expected , where appropriate. Any rough working should be done in this question paper. Question Section A Section B Total 1 2 3 4 5 6 Marks 15 10 12 10 8 9 6 70

2 Section A – Multiple Choice For each question there are four possible answers, A, B, C, and D. Choose the one you consider to be correct. 1 How many subshells and orbitals are there in principal quantum shell number 3? subshells orbitals A 2 4 B 2 6 C 3 6 D 3 9 2 Use of the Data Booklet is relevant to this question. The following are flight paths of charged particles when accelerated in an electric field. Which correctly identifies S, T and U? S T U A 14N+ 14C– 14C2– B 14N– 12C+ 12C2+ C 12C– 14N2+ 14N+ D 14C– 12C+ 14N+ 3 In microwave ovens, the energy produced is absorbed by polar molecules. Which of the following would absorb microwave energy? 1 CO2 2 BrF3 3 BF3 4 SO2 A 1 and 2 only B 1 and 3 only C 2 and 3 only D 2 and 4 only

3 [Turn over 4 Which of the following cannot be explained by hydrogen bonding? A difference in boiling point between ethanol and hexan-1-ol B difference in melting point between H2O and HF C higher than expected relative molecular mass of ethanoic acid in benzene D difference in density between water and ice 5 Trifluorooxonium has the formula OF3n+ and its shape is trigonal pyramidal. What is the value of n in trifluorooxonium? A 1 B 2 C 3 D 4 6 Histamine is produced in the body to help fight infection. Its shape allows it to fit into receptors which expand blood vessels. histamine What are the values of the bond angles x, y and z? x y z A 120° 90° 120° B 109° 109° 107° C 107° 109° 120° D 107° 120° 109°

4 7 Two bulbs R and S, containing Ne and Ar respectively, are connected to a 9 dm 3 vacuum chamber as shown. What will be the total pressure in the vessel when the valves are opened at constant temperature? A 168 kPa B 317 kPa C 356 kPa D 375 kPa 8 In which reactions does NH3 behave as a Brønsted-Lowry acid? 1 HSO4– + NH3 → SO42– + NH4+ 2 Ag+ + 2NH3 → [Ag(NH3)2]+ 3 NH3 + PO43– → NH2– + HPO42– A 1 and 2 only B 1 and 3 only C 2 and 3 only D 3 only 9 Which of the following correctly defines the term relative atomic mass of an element? A the mass of 1 atom of an element relative to the mass of 1 atom of 12C B the mass of 1 mole of atoms of an element divided by 6.02 x 1023 C the mass of 1 mole of atoms of an element relative to 1 12 the mass of 1 atom of 12C D the mass of 1 mole of atoms of an element relative to 1 12 the mass of 1 mole of 12C atoms 10 A carbon sample contains a mixture of 12C and 14C isotopes. When 1.000 g of this sample is burned completely in 16O2, the mass of CO2 formed is 3.55 g. What is the percentage by mass of the 12C isotope in this sample? A 12.4% B 30.6% C 50.5% D 69.4%

5 [Turn over 11 An ion of metal M can be oxidised by potassium manganate(VII) in acid solution to form MO3−. In an experiment, 0.00500 mol of the ion of M required 15.0 cm3 of 0.200 mol dm−3 potassium manganate(VII) for complete reaction. What is the initial oxidation state of the ion of M given that potassium manganate(VII) is reduced to Mn2+? A +1 B +2 C +4 D +7 12 Use of the Data Booklet is relevant to this question. When 0.85 g of ethanol (Mr = 46.0) was burnt completely under a container containing 350 g of water, the temperature of the water rises by 10 °C. The enthalpy change of combustion of ethanol is –1367 kJ mol–1. What is the efficiency of this reaction? A 6.10% B 42.1% C 57.9% D 93.9% 13 In cars, internal combustion engines convert the chemical energy in fuels into kinetic energy. The following reaction takes place in an internal combustion engine. 2C8H18(l) + 25O2(g)  16CO2(g) + 18H2O(g) Which of the following statements are correct about the reaction? 1 Enthalpy change of the reaction is negative. 2 Entropy change of the reaction is negative. 3 The reaction is spontaneous at all temperatures. A 1 and 2 only B 1 and 3 only C 2 and 3 only D 3 only 14 Which of the following processes is always endothermic? A dimerisation of AlCl3 B melting of iron bar C neutralisation between aqueous acid and aqueous alkali D condensation of water

6 15 How many chiral carbon atoms are present in a molecule of vitamin C? vitamin C A 1 B 2 C 3 D 4 END OF SECTION A

7 [Turn over Section B – Structured Questions Answer all questions. 1 Magnesium ethanedioate, MgC 2O4, is an ionic solid present in mineral supplement s to treat magnesium deficiency. (a) (i) Given that there is a plane of symmetry in the structure of ethanedioate ion, draw a ‘dot-and-cross’ diagram to illustrate the bonding in ethanedioate ion. Hence state the shape about each carbon atom. Shape: ………………………………………………………. [2] (ii) Ethanedioate ion reacts with hydrochloric acid in a mole ratio of 1 : 1 in an acid-base reaction. Explain why ethanedioate ion can be described as a Br Ønsted-Lowry base in this reaction and state the formula of its conjugate acid. …………………………………………………………………………………………………. ……………………………………………………………………………………………..… [2] Hydrated salt of magnesium ethanedioate has the formula MgC2O4 • xH2O, where x is an integer. When 7.415 g of hydrated magnesium ethanedioate is heated strongly, it decomposes to form a white alkaline solid P and three gases Q, R and H2O(g). The molecular mass of P is 40.3 g mol-1. When the gases are passed through anhydrous calcium chloride, H2O(g) is completely absorbed and the mass of the calcium chloride increases by 1.800 g. When the remaining gases, Q and R, are subsequently passed through aqueous potassium hydroxide, only Q reacts with potassium hydroxide. Gas R is a poisonous gas. It reacts with oxygen gas to give gas Q. (b) Suggest the chemical formula of P, Q, R and S respectively. P: …………… Q: …………… R: …………… [2]

8 (c) Hence write a balanced chemical equation for the decomposition of MgC2O4 • xH2O. You may use x to balance the equation. ……………………………………………………………………………………………………..[1] (d) Determine the value of x in MgC2O4 • xH2O, showing your working clearly. [3] [Total: 10]

9 [Turn over 2 A methane fuel cell converts the chemical energy of methane and oxygen into electricity. Figure 2.1 shows a simplified diagram of a methane fuel cell. Figure 2.1