CJC Prelim H1 Chem 2008 P1 (with worked soln)

CATHOLIC JUNIOR COLLEGE PRELIMINARY EXAMINATION 2008 CHEMISTRY 8872/01 Higher 1 11 September 2008 Paper 1 Multiple Choice 50 minutes Additional Materials: Multiple Choice Answer Sheet Soft clean eraser Soft pencil (type B or HB is recommended) Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use paper clips, highlighters, glue or correction fluid. Write and shade your name, class and NRIC / FIN on the Answer Sheet. 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. You may use a calculator. There are a total of 9 printed pages including this cover page.

2 Section A For each question there are four possible answers, A, B, C and D . Choose the one you consider to be correct. 1 The Star of Africa , a 530 carats pear-shaped diamond, is the second largest cut diamond in the world. How many atoms of carbon are there in the Star of Africa if 1 carat is equivalent to 200 mg? A 1.06 × 1028 B 1.06 × 1025 C 5.32 × 1027 D 5.32 × 1024 2 An element X can exist in a few oxidation states. 30.00 cm3 of an aqueous solution of 0.400 mol dm -3 X2+ required 40.00 cm 3 of 0.100 mol dm-3 of acidified K2Cr2O7 (aq) for a complete reaction. Cr2O7 2-(aq) + 14H+(aq) + 6e- → 2Cr3+(aq) + 7H2O(l) What is the final oxidation state of X? A +4 B +3 C -1 D 0 3 Which of the following has no unpaired electrons in its valence shell? A Mg + B Si C Cu+ D Fe2+ 4 The successive ionisation energies of an element Y is given below. 787 1577 3231 4356 16091 19784 23783 Which Group does Y belong to? A Group II B Group IV C Group V D Group VI 5 What is the electronic configuration of the atom of the element which is isoelectronic with PH 3? A 1s 2 2s2 2p3 C 1s 2 2s2 2p6 3s2 3p3 B 1s 2 2s2 2p6 D 1s 2 2s2 2p6 3s2 3p6 6 In butanoic acid, CH 3CH2CH2COOH(l), there are covalent bonds, hydrogen bonds and Van der Waals’ forces. Which bonds or forces are broken when butanoic acid undergoes vapourisation? A only hydro