HCI Prelim_H2_CHEM_P1

This document consists of 17 printed pages. HWA CHONG INSTITUTION C2 Preliminary Examinations Higher 2 CANDIDATE NAME CT GROUP 15S CENTRE NUMBER INDEX NUMBER CHEMISTRY Paper 1 Multiple Choice Additional Materials: Optical Mark Sheet (OMS) Data Booklet 9647/01 21 September 2016 1 hour READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Complete the information on the optical mark sheet (OMS) as shown below. 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 correct and record your choice in soft pencil on the OMS. 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.

2 © Hwa Chong Institution 2016 9647 / 01 / C2 Prelim 2016 SECTION A For each question, there are four possible answers A, B, C and D. Choose the one you consider to be correct. 1 Methyl mercaptan, CH3SH, is one of the substances responsible for bad breath and is often used to impart a smell to natural gas in a pipeline. When a sample of 10 cm 3 of CH3SH is exploded with 60 cm 3 of oxygen, the final volume of gas after burning is passed into an excess of aqueous alkali. The chemical equati on for the combustion process is shown below. CH3SH + 3O2  CO2 + SO2 + 2H2O What percentage of the final volume of gas after burning dissolves in the alkali? All gaseous volumes are measured at room temperature and pressure. A 40.0% B 28.5% C 20.0% D 14.3% 2 Figure 1 shows the first six ionisation energies of an element Q while Figure 2 shows the second ionisation energies of eight consecutive elements, including Q, in the Periodic Table. Figure 1 Figure 2 number of electrons removed Which of the elements A, B, C or D could be the element Q? 3 Which statement is not always true when an ionic solid dissolves in water? A Energy is absorbed to separate the ions in the solid. B Energy is absorbed to break the hydrogen bonding between water molecules. C Energy is released when the ions are hydrated. D Energy is released when the ionic solid dissolves completely. second ionisation energy / kJ mol1 proton number A B C D ionisation energy / kJ mol1 1 2 3 4 5 6

3 © Hwa Chong Institution 2016 9647 / 01 / C2 Prelim 2016 4 Which of the following explains the non-ideal behavior of the gases present in the reaction chamber in the Haber process? A the presence of a catalyst