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Unformatted text preview: Section 11/ The d-Block Elements / SKH Bishop Baker Secondary School AL Chemistry Section 11 The d-Block Elements 80 IA Q.4 (c) Write the oxidation number and the coordination number of the central metal in (i) K 2 [RuCl 5 (OH 2 )](s) (ii) [CaEDTA] 2- (aq), where EDTAH 4 represents the following structure : HOOC- CH 2 CH 2- COOH N- CH 2- CH 2- N HOOC- CH 2 CH 2- COOH (2 marks) 80 IB Q.5 (a) Shown below are the basic components of a simple colorimeter : (i) In which order should the components be arranged ? (1 mark) (ii) What is the purpose of the filter B ? (1 mark) (iii) The points on the graph paper below show colorimeter reading against composition for mixtures of e.g. 0.1 M copper(II) sulphate and 0.1 M ethane-1,2-diamine (H 2 NCH 2 CH 2 NH 2 ). (I) Cu 2+ and H 2 NCH 2 CH 2 NH 2 form a complex ion of formula [Cu(H 2 NCH 2 CH 2 NH 2 ) x ] 2+ . What is the value of x ? (1 mark) 1 Section 11/ The d-Block Elements / (II) Through which atoms is the ethane-1,2-diamine molecule bonded to the copper ion ? What essential feature of these atoms makes the bonding possible ? (2 marks) 80 IIB Q.10 (a) Using a diagram of the type d s p show why complexes of transition metals have sometimes two, sometimes four and sometimes six ligands. (8 marks) (b) You are given the following octahedral complexes : (i) M IV en 2 Cl 4 (ii) M II en 2 Cl 2 where en = NH 2 CH 2 CH 2 NH 2 is a bidentate ligand bound to a metal M having different oxidation states. Which of these are electrolytes ? Explain. (2 marks) (b) Why is that these are two forms of complexes with the composition [MA 2 B 4 ] n+ ? (4 marks) (c) Under what conditions might optical activity of inorganic complexes be encountered ? (4 marks) (d) Give one example of the application of a transition metal in industry or the existence of a transition metal ion in a biochemical system and explain its function therein. (2 marks) 81 IB Q.5 (d) Briefly explain the existence in transition metal ions or their compounds of (i) colour, and (ii) magnetic moments. (2 marks) 81 IIB Q.6 (a) Write balanced ionic equations to represent the action of (i) an excess of acid on aqueous solution containing chromate(VI) ions, (iii) an excess of aqueous iodide on aqueous copper(II). (2 marks) (c) Write an ionic equation to demonstrate the oxidizing property of an acidic solution of manganate(VII) (permanganate) ion. (1 mark) 81 IIB Q.9 A quantity of cobalt(II) chloride hexahydrate was dissolved in 20 cm 3 of water, giving a pink solution A (0.035 M). To this pink solution, 10 cm 3 of an aqueous solution of ammonium carbonate (0.2 M) and 50 cm 3 of concentrated ammonia were added. The solution immediately turned blue in colour. This was solution B ....
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This note was uploaded on 08/17/2011 for the course CHEM 100 taught by Professor Fleet during the Fall '08 term at Oxford University.
- Fall '08
- Oxidation Number