MI_H1_CHEM_8873_01_Answers

Class Adm No Candidate Name: This question paper consists of 13 printed pages and 1 blank page. 2018 End-of-Year Exams Pre-University 2 H1 CHEMISTRY 8873/01 Paper 1 Multiple Choice 13 Sept 2018 1 hour 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 in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, class and admission number in the spaces provided at the top of this page and on the Multiple Choice Answer Sheet provided. 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 Multiple Choice Answer Sheet provided. Read the instructions on the Multiple Choice 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 question paper. The use of an approved scientific calculator is expected, where appropriate. FOR EXAMINER’S USE TOTAL (30 marks)

2 Section A For each question there are four possible answers, A, B, C, and D. Choose the one you consider to be correct. 1 According to the equation below, how many moles of potassium chlorate, KC lO3, must be decomposed to generate 1000 cm3 of O2 gas at standard temperature and pressure? 2KClO3(s)  2KCl(s) + 3O2(g) A 2 3 ൬ 1 24൰ mol B 3 2 ൬ 1 24൰ mol C 2 3 ൬ 1 22.7൰ mol D 3 2 ൬ 1 22.7൰ mol 2 Use of the Data Booklet is relevant to this question. It is suggested that SO2 which contributes to acid rain, could be removed from a stream of waste gases by bubbling the gases through 0.25 mol dm -3 KOH, thereby producing K 2SO3. What is the maximum mass of SO2 that could be removed by 1000 dm3 of the KOH solution? A 4.0 kg B 8.0 kg C 16.0 kg D 20.0 kg

3 [Turn over 3 To determine the molar mass of a weak monoprotic acid, a student titrated 25.0 cm3 of the acid with aqueous NaOH. Which of the following are appropriate indicators that could be used for the titration? 1 Phenolphthalein 2 Methyl Orange 3 Bromothymol blue A 1 only B 1 and 2 only C 2 and 3 only D 1, 2 and 3 4 A sample of 30.0 cm 3 of 0.050 mol dm -3 iron( II) sulfate is titrated against 0.025 mol dm -3 potassium manganate(VII) solution. It is found that 20.0 cm 3 of the manganate(VII) solution is required to reach end point. What is the oxidation number of manganese at the end point? A +2 B +3 C +4 D +5

4 5 The number of orbitals of a principal quantum number is dependent on the typ