RI Prelim_P1_QP

-1- RAFFLES INSTITUTION 2015 YEAR 6 PRELIMINARY EXAMINATION HIGHER 2 CHEMISTRY 9647/01 Paper 1 Multiple Choice 28 September 2015 1 hour Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Do not open this question booklet until you are told to do so. Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, class and index number in the spaces provided on the Answer Sheet. There are forty questions on this paper. Answer all questions. For each question there are four possible answers A, B, C and D. Choose the one you c onsider 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. This document consists of 16 printed pages.

-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 Manganese occurs naturally in many oxides. A sample of a manganese oxide ore consists of a mixture of manganosite (MnO) and braunite (Mn 2O3), and contains Mn and O in the molar ratio of 0.7:1. What is the molar ratio of Mn2+:Mn3+ in the ore? A 1:6 B 1:5 C 1:4 D 1:3 2 Use of the Data Booklet is relevant to this question. Uranium, U, is able to form water-soluble salts in which it exists in different oxidation states. In an experiment, 20.00 cm 3 of 0.100 mol dm –3 Un+ ions was found to react with 40.00 cm 3 of 0.0200 mol dm–3 MnO4 – ions in acidic medium. If UO2 2+ ions were produced in the reaction, what is the value of n in Un+? A 4 B 3 C 2 D 1 3 Use of the Data Booklet is relevant to this question. In which of the following pairs do the two species contain the same number of unpaired electrons? A C+, N B O, P+ C Cr+, Fe2+ D Mn3+, Co+ 4 The successive ionisation energies, in kJ mol–1, of an element Z in period 3 are given below. 770 1542 3208 4331 16091 19805 23780 29287 Which of the following statements about Z is correct? A Z is a good conductor of electricity. B The chloride of Z dissolves in water to form its oxide and white fumes. C The oxide of Z reacts with dilute potassium hydroxide. D Z has a simple molecular structure. 5 Which feature is present in the ions CO3 2–, SO3 2–, NO3 – and HCO2 –? A all