2019 CJC Prelim H2 Chem P1 QP

1 [Turn over CANDIDATE NAME CLASS 2T CHEMISTRY 9729/01 Paper 1 Multiple Choice Tuesday 3 September 2019 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, class and NRIC/FIN number on the Answer Sheet in the spaces 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 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. This document consists of 15 printed pages and 1 blank page. Catholic Junior College JC 2 Preliminary Examinations Higher 2

2 9729/01/CJC JC2 Preliminary Examination 2019 1 In a titration experiment, 15 cm3 of 0.10 mol dm−3 phosphorous acid, H3PO3 was found to react with 10 cm3 of 0.30 mol dm−3 sodium hydroxide, NaOH. Using this information, deduce the formula of the salt formed in this neutralisation process. A NaH2PO3 C Na3PO3 B Na2HPO3 D Na3PO4 2 50 cm3 of a mixture of ethene and propane gas were exploded in excess oxygen. The volume of the residual gases was found to be 200 cm3. On being shaken with potassium hydroxide, the final volume was found to be 90 cm3. What is the composition of the mixture? (All volumes are measured at r.t.p) volume of ethene volume of propane A 10 40 B 20 30 C 30 20 D 40 10 3 Plutonium-239 is a radioactive substance that emits a constant stream of –particles which are similar to the nucleus of 4He. Rubidium-87 is another radioactive substance that emits –particles which can be considered as electrons. A small amount of Plutonium -239 and Rubidium -87 are separately placed in an ionisation chamber to emit a constant stream of radiation and the emitted particles are passed through an electric field. What would be the path of the emitted particles in the electric field? Plutonium-239 (–particles) Rubidium-87 (–particles) A 1 2 B 1 3 C 4 1 D 3 1

3 9729/01/CJC JC2 Preliminary Examination 2019 [Turn over 4 Diazene has a molecular formula of N 2H2. Given that the nitrogen and hydrogen show their usual valencies, which of the following correctly describes the shape and bond angle around each central atom? shape bond angle A bent 110⁰ B linear 180⁰ C tetrahedral 109⁰ D trigonal planar 120⁰ 5 Which of the following contains delocalised electrons? 1 Graphite 2 Sodium 3 Ethanoate ion 4 Cyclohexene A 1 and 2 only B 2 and 3 only C 1, 2 and 3 only D 3 and 4