JJC_H1 Chemistry 8872_H1 Prelim Paper 1 and Solutions

JURONG JUNIOR COLLEGE PRELIMINARY EXAMINATION 2008 H1 CHEMISTRY PAPER 1 8872 / 1 Friday 22 August 2008 50 minutes INSTRUCTIONS TO CANDIDATES: Do not open this question booklet until you are told to do so. Write your name and class on the answer sheet in the spaces provided. There are 30 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. INFORMATION FOR CANDIDATES: Each correction answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done in this booklet. A Data Booklet is provided. _____________________________________________________________________ This question booklet consists of 10 printed pages, including this page. [Turn over]

SECTION A (25 MARKS) For each question there are four possible answers, A, B, C and D. Choose the one you consider to be correct. 1. How many atoms of carbon are present in 18 g of glucose C6H12O6? A 6.0 x 1022 B 3.6 x 1023 C 6.0 x 1023 D 3.6 x 1024 2. What is the minimum volume of air required for complete combustion of 10 cm 3 of a hydrocarbon, C3H4? Assume that air contains one-fifth oxygen by vo lume and that both gases are measured at the same temperature and pressure. A 40 cm3 B 50 cm3 C 200 cm3 D 250 cm3 3. Nitrogen dioxide reacts with iodide ions under acidic conditions according to the equation shown. NO2 + 2I− + 2H+ Æ NO + I2 + H2O How many moles of electrons are gained by one mole of nitrogen dioxide? A 1 B 2 C 3 D 4 4. The electronic configurations of four elements are given. Which of these elements has the lowest first ionisation energy? A 1s2 2s2 2p3 B 1s2 2s2 2p4 C 1s2 2s2 2p6 3s2 D 1s2 2s2 2p6 3s2 3p1 Page 2 of 10

5. Use of the Data Booklet is relevant to this question. The successive ionisation energies, in kJ mol−1, of an element X are given below. 947 1798 2735 4837 6043 12310 13298 What could X be? A 33As B 40Zr C 49In D 52Te 6. Which of the following particl es would, on losing an electron, have a half-filled set of p orbitals? A C− B N C N− D O+ 7. Silicon carbide (carborundum) has a similar structure to diamond. Silicon carbide can be used as A a lubricant B a tip for cutting tools C an electrical conductor D a substitute for pencil ‘lead’ 8. Which of the following molecules do not have all the atoms lying on the same plane? A H 2O B PH3 C AlCl3 D ICl3 9. Which of the following molecules will not form a hydrogen bond with another of its own molecules? A CH 3CHO B CH3NH2 C CH3OH D NH3 Page 3 of 10

10. Zinc is extracted from zinc sulphide by a process which beg