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OCR A Jan 2013 Paper 5 Q1
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![Answer all the questions. This question refers to chemistry of d-block elements in Period 4 (ScZn). (a) For each statement below, select the symbols of the correct element(s). (i) The element that has atoms containing six electrons in the 3d sub-shell.[1] (ii) Two elements that have atoms with two unpaired d electrons.and[2] (iii) The element with ions that form a blue complex with chloride ions. (iv) The element X that forms an oxide with the formula X3O4 with the molar mass of 228.7 g mol1.[1][1] (v) The element that has atoms with an average mass of 8.641023 g.[1] (b) The flowchart below shows three reactions of the complex ion [Cu(H2O)6]2+. In the boxes below, write down the formulae of the species formed. [Cu(H2O)6]2+ pale blue solution NH3(aq) HCl (aq) NaOH(aq) deep blue solution yellow solution pale blue precipitate [3]OCR 2013<br />
(c) The answers to this question all refer to complex ions of nickel. (i) State the shape of the complex ion [Ni(H2O)6]2+.[1] (ii) What is the formula of the complex ion of Ni2+ containing six fluoride ligands?[1] (iii) Show the 3-D shapes of the stereoisomers of the complex ion [Ni(en)3]2+. (en = H2NCH2CH2NH2) [2] [Total: 13]OCR 2013 Turn over<br />](https://learnah.org/wp-content/uploads/2018/08/OCR_5_QP_JAN13_question_1-0.jpg)
![F325 Question (a) (i) Fe (cid:57) (a) (a) (a) (ii) Ti (cid:57) Ni (cid:57) (iii) Co (cid:57) (iv) Mn (cid:57) (a) (v) Cr (cid:57) (b) [Cu(NH3)4(H2O)2]2+ (cid:57) 2 (cid:57) CuCl4 deep-blue solution: yellow solution: pale-blue precipitate: Cu(OH)2 (cid:57) (i) octahedral (cid:57) (ii) NiF6 4 OR [NiF6]4 (cid:57) (c) (c) Mark Scheme January 2013 Answer Marks Guidance Throughout Q1 IGNORE variations in caps and small letters ALLOW name: iron DO NOT ALLOW ions, e.g. Fe2+ ALLOW names: titanium and nickel DO NOT ALLOW ions ALLOW name: cobalt ALLOW Co2+ ALLOW name: manganese ALLOW Mn3O4 ALLOW name: chromium DO NOT ALLOW [Cu(NH3)4]2+ OR [Cu(NH3)6]2+ [ ] not required ALLOW round brackets around any atom e.g. ALLOW [CuCl4]2; Cu(Cl4)2 DO NOT ALLOW [Cu(Cl)4]2 OR [Cu2+(Cl)4]2 ALLOW Cu(OH)2(H2O)4 OR [Cu(OH)2(H2O)4] 4 charge required ALLOW [Ni(F)6]4; ALLOW NiF6 ALLOW round brackets DO NOT ALLOW Fl for F DO NOT ALLOW [Ni(F)6]4 OR [Ni2+(F)6]4 4<br />
F325 Question (iii) 1 (c) Mark Scheme January 2013 Answer 2+ NH2 Ni H2 N NH2 N H2 CH2 CH2 H2C H2C H2 N H2N Ni N H2 H2N H2 C H2C H2N H2N H2C C H2 2+ H2 C CH2 NH2 NH2 CH2 C H2 (cid:57) (cid:57) one mark for each structure 2nd structure must be correct mirror image of 1st structure Marks Guidance 1 mark for 3D diagram with ligands attached for ONE stereoisomer Must contain 2 out wedges, 2 in wedges or dotted lines and 2 lines in plane of paper IGNORE any charges shown ALLOW any attempt to show bidentate ligand. Bottom line shown in diagrams below. IGNORE connectivity: H2N OK en en Ni Ni en Ni Ni en ALLOW en en ALLOW 2 x en seen in each bridge Total 13<br />](https://learnah.org/wp-content/uploads/2018/08/OCR_5_QP_JAN13_answer_1-0.jpg)
