NJC Prelims Paper 1_QP

NJC/H2 Chem Preliminary Examination/02/2021 1 [Turn over NATIONAL JUNIOR COLLEGE SH2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME SUBJECT CLASS REGISTRATION NUMBER CHEMISTRY Paper 1 Multiple Choice Additional Materials: Optical Answer Sheet Data Booklet 9729/01 15 September 2021 1 hour READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, subject class and registration number on the Answer Sheet in the spaces provided unless this has been done for you. There are thirty 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 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 calculator is expected, where appropriate. Instructions on how to fill in the Optical Mark Sheet Shade the index number in a 5 digit format on the optical mark sheet: 1st digit and the last 4 digits of the Registration Number. Example: Student Examples of Registration No. Shade: 2005648 25648 This document consists of 12 printed pages.

NJC/H2 Chem Preliminary Examination/02/2021 2 1 A sample of element sulfur contains four isotopes of the following composition. relative isotopic mass relative abundance 32 95.02 33 0.76 34 4.20 36 0.02 What is the relative atomic mass of sulfur in this sample? A 32.07 B 32.08 C 32.09 D 32.10 2 When 15 cm3 of a gaseous organic compound were completely burnt in an excess of oxygen, 30 cm3 of carbon dioxide and 15 cm3 of nitrogen were formed, all volumes being measured at the same temperature and pressure. Which could be the formula of the organic compound? A C2H4N2 B C2H7NO C C3H7NO D C3H6N2 3 Which ion has less electrons than neutrons and less neutrons than protons? ion neutrons nucleons A A− 18 37 B B2+ 17 34 C C3+ 16 33 D D3− 16 31 4 Covalent bonds are formed by orbitals overlap. CC C CH3 H H CC H H H1 2 3 4 5 6 Which statement does not describe the molecule above? A The V bond between C1–C2 is formed by 2sp2–2sp2 overlap. B The V bond between C2–C3 is stronger than that between C5–C6. C The S bond between C4–C5 is formed by 2sp–2sp2 overlap. D The V bond between C6–H is formed by 2sp3–1s overlap.

NJC/H2 Chem Preliminary Examination/02/2021 3 [Turn over 5 Which options contain a polar and a non-polar molecule? 1 CO2, H2O 2 SO2, PCl5 3 CH2Cl2 , SiCl4 A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 1 only 6 The value of pV is plotted against p for two gases, an ideal gas and a non-ideal