RI_H2_CHEM_P1 Prelim

-1- RAFFLES INSTITUTION 2011 YEAR 6 PRELIMINARY EXAMINATION HIGHER 2 CHEMISTRY 9647/01 Paper 1 Multiple Choice 26 September 2011 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 consider to be correct and record your choice with a 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 17 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 2.8 g of a metal, M, combines with 0.8 g of oxygen to form the oxide MO. The metal, M, also forms a second oxide in which the metal and oxygen are present in the ratio 7:3 by mass. What is the formula of the second oxide? A MO 2 B M2O C M2O3 D M3O2 2 Use of the Data Booklet is relevant to this question. When x mol of vanadium is added to a solution containing y mol of vanadium( III ) ions, vanadium( II ) ions are formed in the resultant solution. Which of the following are possible values of x and y if vanadium reacts completely and the resultant solution contains equal number of moles of vanadium( III ) ions and vanadium( II ) ions? x y A 1 2 B 1 3 C 1 5 D 2 3 3 Bromine trifluoride is a liquid at room temperature . It shows an electrical conductivity high enough to indicate that some auto-ionisation o ccurs, which is usually represented by the following equation: 2BrF 3 ⇋ BrF 2 + + BrF 4 – Which of the following is correct regarding BrF 3, BrF 2 + and BrF 4 – ? A BrF 3 is planar while BrF 4 – is non-planar. B BrF 2 + is linear while BrF 4 – is tetrahedral in shape. C The F–Br–F bond angle in BrF 3 is smaller than that in BrF 4 – . D There are more lone pairs of electrons around the Br atom in BrF 3 than that in BrF 2 +. 4 Which of the following cannot be explained by hydrogen bonding? A the existe