ACSI Paper 1 Prelim Suggested Solutions

1 Anglo-Chinese School (Independent) Year 6 PRELIMINARY EXAMINATION 2023 INTERNATIONAL BACCALAUREATE DIPLOMA PROGRAMME CHEMISTRY HIGHER LEVEL PAPER 1 Monday 12 th September 2022 1 hour Additional materials: Multiple choice answer sheet Soft clean eraser Soft pencil (type 2B recommended) INSTRUCTIONS TO CANDIDATES Do not open this booklet until you are told to do so. Shade your Candidate number on the multiple choice answer sheet provided. There are forty questions in this paper. Answer all the 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. INFORMATION FOR CANDIDATES 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. A copy of the periodic table is provided for reference on Page 2 of the examination paper. Calculators are not allowed to be used in this paper. This question paper consists of 18 printed pages, including the cover page.

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3 1. In which of the following species would nitrogen be reduced if converted to N2O4? A. NH 3 B. NO C. NO3− D. NO2− 2. How many electrons are needed when the following half-equation is balanced using the lowest possible whole numbers? __SO2 + __H2O ⟶ ___SO42− + ___H+ + ___e− A. 1 B. 2 C. 3 D. 4 3. Typically, when a person coughs, he first inhales about 2.0 dm3 of air at 1.0 atm and 25 oC. In the lungs, the air is warmed to 37 oC and compressed to a volume of about 1.7 dm3 by the action of the diaphragm and chest muscles. The sudden opening of the vocal cord then releases the air explosively. Just prior to this release, what is the approximate pressure (in atm) of the gas inside the lungs? A. 1.0×2.0×37 25×1.7 B. 1.0×2.0×310 298×1.7 C. 25×1.7 1.0×2.0×37 D. 298×1.7 1.0×2.0×310

4 4. Which of the following statements contains one mole of the stated particle? [At SATP, one mol of gas occupies 24.0 dm3] A. Molecules in 19.00 g of fluorine gas. B. Electrons in 24.0 dm 3 of hydrogen gas at SATP. C. Neutrons in 1.00 g of helium gas. D. Protons in 2.018 g of neon gas. 5. The first eight successive ionization energies for an atom are shown. In which group is the atom found? A. 15 B. 16 C. 17 D. 18

5 6. How many electrons are there in all the d orbitals in a xenon atom? A. 10 B. 18 C. 20 D. 36 7. Which trend is correct across the period? A. Atomic radius decreases B. Electronegativity decreases C. Ionic radius increases D. Melting point decreases 8. Which of the following affects the colour of the complex formed by a particular transition metal? I. Oxidation state of metal II. Type of ligand III. Geometry of the complex A. I and II only B. I and III only C. II and III only D. I, II an