Transition metals

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Mind Map on Transition metals, created by Fizza A on 23/02/2016.
Fizza A
Mind Map by Fizza A, updated more than 1 year ago
Fizza A
Created by Fizza A almost 9 years ago
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Resource summary

Transition metals
  1. DEFINITION: a metal that can form one or more stable ions with a partially filled d-subshell
    1. SCANDIUM AND ZINC: their stable ions do not have a partially filled d-subshell so they are not transition metals
    2. PROPERTIES
      1. PHYSICAL: good conductors of heat and electricity, hard, strong, high m.p and b.p
        1. CHEMICAL: can form complex and coloured ions, variable oxidation states, catalysts
        2. COMPLEX IONS: central metal ion surrounded by coordinately bonded ligands
          1. LIGAND: an atom, ion or molecule that has a lone pair of electrons that forms a coordinate bond with a transition metal
            1. UNIDENTATE: can only form one coordinate bond e.g. water, ammonia, chloride ions
              1. BIDENTATE: form two coordinate bonds
                1. MULTIDENTATE: can form more than one coordinate bonds e.g. EDTA4-
                2. CO-ORIDNATION NUMBER: the number of coordinate bonds formed to a central metal ion
                  1. SHAPES: small ligands - octahedral. Large ligands - tetrahedral. Square planar - cisplatin.
                  2. FORMATION OF COLOURED IONS
                    1. COLORIMETRY: can be used to determine the concentration of a solution and/or find the ratio of metal ions to ligands (formula)
                      1. The more conc. a solution, the more light it absorbs so less light will pass through the solution.
                        1. METHOD: add an appropriate ligand to intensify colour, make up solutions of known conc., measure absorption and transmission, plot calibration curve, measure absorption of unknown and compare
                          1. USEFUL METHOD AS: easy to get a lot of readings and quick, doesn't interfere with any reactions, doesn't use up any substances, can measure very low conc.
                          2. CATALYSTS
                            1. HETEROGENOUS: catalyst is in a different phase to the reactants.
                              1. USE OF SUPPORT MEDIUMS: reaction happens on the surface of catalysts so increasing the surface of the catalyst will increase the ROR. To do this a support medium is used e.g. catalytic converters have a ceramic lattice coated with a thin layer of rhodium
                              2. HOMOGEOUS: catalyst is in the same phase as the reactants
                                1. CATALYST POISONING: Impurities can bind to the active sites on the surfaces of heterogenous catalysts and block the reactants from being adsorbed - reduces the surface area available to reactants.
                                  1. CATALYTIC CONVERTERS: lead can coat the surface of catalyst
                                    1. HABER PROCESS: hydrogen produced from methane which is produced from natural gas so contains impurities including sulphur compouds. Sulphur is adsorbed onto the iron forming iron sulphide and reducing efficiency of catalyst
                                    2. AUTOCATALYSIS: one of the products is a catalyst for the reaction. Reaction starts slowly at the uncatalysed stage, reaction speeds up at the catalysed stage
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