JC2 Chemistry H1 2017 Nanyang QP

[Turn Over NANYANG JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 1 CHEMISTRY 8872/01 Paper 1 Multiple Choice 25 Sep 2017 50 minutes 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, CT and NRIC / FIN on the Answer Sheet in the spaces provided. There are thirty questions in 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 calcul ator is expected, where appropriate. This document consists of 14 printed pages.

2 NYJC 2017 H1 Chemistry 8872/01 PRELIM Section A For each question there are four possible answers, A , B , C , and D . Choose the one you consider to be correct. 1 Use of the Data Booklet is relevant to this question . The compound S 2 O 7 is hydrolysed by water to pr oduce sulfuric acid and oxygen. What volume of oxygen, measured at ro om temperature and pr essure, is evolved when 0.352 g of S 2 O 7 is hydrolysed? A 12 cm 3 B 24 cm 3 C 48 cm 3 D 96 cm 3 2 Tanzanite is used as a gemstone for jewell ery. It is a hydrat ed calcium aluminium silicate mineral with a chemical formula of Ca 2 A l a Si b O 12 (OH).6½H 2 O. Tanzanite has M r of 571.5. Its chemical composition is 14.04% calcium, 14.17% aluminium, 14.75 % silicon, 54.59% oxygen and 2.45% hydrogen. What are the values of a and b? a b A 1 1 B 2 3 C 3 3 D 6 1 3 Ammonium nitrate, NH 4 NO 3 , can decompose explosively when heated. NH 4 NO 3  N 2 O + 2H 2 O What are the changes in the oxidation numbers of the two nitrogen atoms in NH 4 NO 3 ? A − 2, − 4 B +2, +6 C +4, − 6 D +4, − 4

3 NYJC 2017 H1 Chemistry 8872/01 PRELIM [Turn Over 4 Tritium is the isotope of hydrogen 3 H. Which of the following is the same for a 4 He atom and a 3 H atom? A the relative atomic mass B the number of electrons C the number of protons D the number of neutrons 5 Use of the Data Booklet is relevant to this question. What could be the proton number of an elem ent that has three unpaired electrons in each of its atoms? A 5 B 13 C 15 D 21 6 Why does aluminium chloride, A l 2 C l 6 , sublime at a relatively low temperature of 180  C? A The intermolecular forces between the A l 2 C l 6 molecules are weak. B The co-ordinate bonds between aluminium and chlorine are weak.