MJC_2008 H2 Chem Prelim Paper 1 (questions)

Class Reg Number Candidate Name _____________________________ 17 September 2008 1 hour Paper 1 Multiple Choice Questions Additional Materials Data Booklet INSTRUCTION TO CANDIDATES Write your name, class and register number in the spaces provided at the top of this page. There are forty questions in this section. Answer all questions. For each question, there are four possible answers labelled A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the OMR answer sheet. Read very carefully the instructions on the OMR answer sheet. You are advised to fill in the OMR Answer Sheet as you go along; no additional time will be given for the transfer of answers once the examination has ended. Use of OMR Answer Sheet Ensure you have written your name, class register number and class on the OMR Answer Sheet. Use a 2B pencil to shade your answers on the OMR sheet; erase any mistakes cleanly. Multiple shaded answers to a question will not be accepted. For shading of class register number on the OMR sheet , please follow the given examples: If your register number is 1, then shade 01 in the index number column. If your register number is 21, then shade 21 in the index number column. Meridian Junior College JC2 Preliminary Examination 2008 H2 Chemistry 9746 This question paper consists of 22 printed pages. 1

1 A 10 cm 3 sample ethanethiol was exploded with 80 cm 3 of oxygen according to the given equation CH 3CH2SH + 9 2 O2 → 2 CO 2 + SO2 + 3 H2O The resultant gas mixture is cooled and passed through aqueous sodium hydroxide. What would be the final volume of the resultant mixt ure gases at r.t.p after passing through aqueous sodium hydroxide? A 10 cm3 B 35 cm3 C 45 cm3 D 75 cm3 2 The solubility of a gas in water can be ca lculated using its Henry’s Law constant, Kh, which is defined as: K h = concentration of the gas in water partial pressure of the gas in air The Kh for CO2 is 3.8 x 10-2 mol dm-3 atm-1. In an enclosed system containing car bon dioxide, hydr ogen and nitrogen and argon, the volumes of each gases were found to be 3 dm 3, 1 dm 3, 75 dm 3 and 0.5 dm3 respectively. Using Kh, what is the concentration (in mol dm-3) of dissolved carbon dioxide in water when the total atmospheric pressure is 2 atmospheres? A 1.43 x 10 -3 B 2.87 x 10 -3 C 3.00 x 10 -3 D 1.14 x 10 -1 2

3 Figure 1 shows the first 8 ionisation energies of an element J while Figure 2 shows the boiling point of 8 consecutive elements (including element J). D A With reference to Figure 2, which of the options A, B, C or D corresponds to the boiling point of element J? 4 The structure of tetr asulphur tetranitride, S4N4, is shown below. N S N S S N S N x y