MI_2008_PU2_ Promotional_H1Chem P1_ans

Class Adm No Candidate Name: _______________________ Promotional Examinations 2008 Pre-university 2 CHEMISTRY HIGHER 1 8872/1 Monday 8 th Sept 2008 50 minutes Additional materials: Answer paper Data Booklet 1 piece of foolscap paper READ THESE INSTRUCTIONS FIRST Do not open this booklet until you are told to do so. Write your name, index number and cla ss on the answer sheet in the spaces provided and at the top of this page. There are thirty questions in 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. This question paper consists of 12 printed pages.

Section A: Multiple Choice Questions (30m) For each question, there are 4 possible answers, A, B, C and D. Choose the one that you consider correct. 1. Which of the following contains 9.03 × 10 21 of atoms? A 2.25 g of methane B 0.6375 g of ammonia C 336 cm 3 of argon gas at standard temperature and pressure D 3.60 dm 3 of fluorine gas at room temperature and pressure 2. On heating chromite, FeCr 2O4 with sodium carbonate in air, the following reaction occurs: 4FeCr2O4 + 8Na2CO3 + 7O2Æ 8Na2CrO4 + 2Fe2O3 + 8CO2 Which species is oxidised and which species is reduced in this process? Species oxidised Species reduced A Chromium only Carbonate ion only B Chromium only Carbonate ion and oxygen C Chromium and iron Oxygen only D Chromium and iron Carbonate ion and oxygen 3. The successive ionization energies, in kJ mol -1, of an unknown element E are given below. 420 3100 4400 5900 8000 9600 11400 13300 Which of the following statements about E is correct? A E is in group II of the Periodic Table. B The oxide of E is an amphoteric oxide. C The chloride of E hydrolyses in water to give an acidic pH. D Element E can conduct electricity in the solid and molten state. [Turn over 2

4. Which electronic configuration is t hat of an atom of an element which is isoelectronic with H2S? A 1s 2 2s2 2p6 3s2 B 1s 2 2s2 2p6 3s2 3p2 C 1s 2 2s2 2p6 3s2 3p4 D 1s 2 2s2 2p6 3s2 3p6 5. Which of the following pairs contai ns a compound held by ionic attractions and a compound held by permanent dipole-permanent dipole attractions? A sodium chloride, tetrachloromethane B strontium, bromoethane C aluminium fluoride, phosphorus trichloride D sodium ethanoate, beryllium hydride 6. How many σ and π bonds are there in linear C2H2 molecule? A 2 σ and 2π B 2 σ and 3π C 3 σ and 1π D 3 σ and 2π 7. Why is the boiling point of butanone (79.6 oC) higher than that of pentane (36.1oC)? A The relative molecular mass of bu tanone is higher than that