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54 Cards in this Set
- Front
- Back
Deifne transition metal. |
Any metal which can form at least 1 stable complex ion and has an incomplete D sub level. |
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Where in the periodic table are transition metals found? |
The D block. |
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Which of the period 4 elements are transition metals? |
All of them apart from Sc and Zn (the two bookends). |
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What 2 exeptions are there in transition metals to the rule that the 4s shell fills before the 3d shell? |
Copper, has 1 electron in 4s and 1 in 3d. Chromium, has a full 3d and 1 in the 4s. |
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In what order are electrons removed when transition metals form positive ions? |
The 4s electrons are removed and then the sd electrons are removed. |
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Why are Scandium and Zinc not transition metals? |
They do not form stable ions with incomplete d sub levels. |
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Name two physical properties of transition metals. |
High density High melting and boiling points |
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Name 4 chemical properties of transition metals. |
Form complex ions Form coloured ions Can work as catalysts Variable oxidation states |
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Why is it that transition metals can show variable oxidation states? |
4s and 3d are of similar energies and therefore electrons can be gained or lost using similar amounts of energy. |
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What is a complex ion? |
A metal ion surrounded by co-ordinately bonded ligands. |
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What is a ligand? |
A molecule, atom or ion that donates a pair of electrons to a central metal ion via a coordinate bond. |
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What is a co-ordinate bond? |
A covalent bond where both electrons from the shared electron pair come from one atom. |
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What is a monodentate ligand?
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A monodentate ligand is a ligand which can form one co-ordinate bond. |
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Give 3 examples of monodentate ligands. |
Ammonia Water Cl- ions |
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What is a multidentate ligand? |
A ligand which can form multiple co-ordinate bonds with a central metal ion. |
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Give one example of a multidentate ligand. |
EDTA (4-) ethylenediaminetetra-acetic acid. |
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How many co-ordinate bonds can EDTA (4-) form, and where do they come from? |
6 4 from lone pairs on oxygen 2 from lone pairs on nitrogen |
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What is a bidentate ligand? |
A ligand which can form TWO co-ordinate bonds. |
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Give an example of a bidentate ligand and explain its structure.
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Ethane- 1,2- diamene 2 carbon chain with two NH3 molecules on the ends (NH2 CH2 CH2 NH2) Lone pairs on the nitrogens |
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How many co-ordinate bonds can the ligand ethane- 1,2- diamine form? |
2 |
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How do we display the overall charge of a complex ion? |
Outside of a pair of square brackets. |
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How do you work out the oxidation state of the transition metal ion within the complex? |
Total charge of the complex- charge of all the ligands. |
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What does the co-ordination number of a complex ion show? |
How many co-ordination bonds are formed around the central ion. |
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What are the 3 most common co-ordination numbers? |
6, 4 and 2. |
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Which ligands will form a complex ion with co-ordination number 6. |
EDTA (4-) Small monodentate ligands such as water, ammonia and chloride ions. |
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Which ligands will form a complex ion with co-ordination number 4. |
Large monodentates such as chloride ions. |
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Which ligands will form a complex ion with co-ordination number 2. |
Ethane- 1,2- diamene. Complexes with Ag |
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What shape do complex ions with co-ordination number 6 form. |
Octohederal. |
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What name is given to complexes involving a metal ion bound to 6 water ligands. |
Hexaqua complex. |
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What shapes to complex ions with co-ordination number 4 usually take? |
Tetrahederal and less commonly square planar. |
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Give one example of a complex ion with coordination number 4, that takes a square planar shape. |
Cisplatin. |
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What shape do ions with co-ordination number 2 usually take? |
Linear planar. |
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What metal usually forms complexes with co-ordination number 2, and a linear planar shape. |
Ag (silver). |
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What is optical isomerism? |
A type of stereoisomerism Stereoisomerism= same molecular formula, different arrangement of bonds in space. |
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When are complex ions able to form enantiomers. |
When they have 3 bidentate ligands in an octohederal shape. |
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Name the 2 types of stereoisomerism which transition metal ion complexes can undergo. |
Optical E/Z |
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Describe the structure of Cisplatin. |
Cisplatin is a Z (cis) isomer. It has a central platinum ion with 2 ammonia ligands and 2 Chloride ion ligands. Square planar shape. |
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What is Cisplatin used for? |
Cisplatin is used to treat cancer by preventing uncontrolled cell division. |
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What is transplatin? |
The E (trans) isomer of cisplatin which holds different biological effects. |
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Name 2 downsides of Cisplatin? |
It also prevents cell reproduction in healthy, normal cells. Kidney damage. |
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When can octohederal complex ions form cis/trans isomers? |
4 ligands of 1 type and 2 of another type. Two odd ligands opposite sides= trans (E) Two odd ligands same side= cis (Z) |
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In complex ions, what happens which causes the 3d shell of the transition metal to seperate into 2 energy levels? |
The attatchment of ligands. |
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What property of transition metal ions allows them to form coloured ions? |
The 3d energy sub level seperates into 2 seperate energy levels from which electrons can jump between. |
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When the 3d sub shell in the transition metal of a complex ion seperates into 2, which energy level do electrons generally occupy? |
The lower energy level. |
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Where do electrons in a complex ion gain energy from, in order to breach the energy gap between the 2 3d energy levels? |
Visible light. |
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In terms of complex transition metal ions, what is ΔE? |
Energy required to breach the gap between the 2 energy levels which are created when the 3d energy level is seperated into 2. |
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What is the equation used to work out ΔE, in terms of transition metal ions? |
ΔE= hv= hc/λ |
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In the equation 'ΔE= hv= hc/λ' What do all of the letters represent? |
ΔE = energy gap h = plancks constant (Js) v = freq of light absorbed (Hz) c = speed of light (ms-1) λ= Wavelength of light (m) |
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What is plancks constant? |
6.63 x 10-34 js |
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What happens when light hits a transition metal ion? Why? |
Some of the frequencies of light are absorbed as electrons jump from one energy level to another, in the 2 energy levels that are created when the 3d sub level is split. |
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What determines which frequences of light are absorbed by a complex transition metal ion? |
The size of the energy gap (ΔE) |
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What happens to the frequences of light which are not absorbed by the transition metal ion? |
They are reflected and this is what we see. |
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In a transition metal complex ion, what colour would the ion be if the 3d sub level was full or completely empty? |
The ion would be colourless or white, as there will be no electrons to jump between the 2 energy levels that are created when the 3d sub level splits. No jumping of electrons= no light absorption. |
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Name 4 factors which affect the size of the energy gap in the 3d subshell of a transition metal ion. |
Central metal ion Oxidation state Ligands Co-ordination number |