Transition Elements Flashcards
Properties of d block elements
Typical metal
Durable Maleable Conduct High melting and boiling point Shiny Ductile
How do transition metal ions always form
Lose electrons from 4s orbital
What makes a d block element a transition element
Able to form multiple ions with partially filled 3d orbitals
What d block elements are not transition elements and why
Zn and Sc
Form ions with half filled or full 3d subshell
What are the properties of transition elements
Compounds with different colours
Ions with diff oxidation states
Act as catalysts
How does the number of possible oxidation states vary across the d block
Increases from ti to Mn
Decreases from Mn to cu
What ion do all transition elements form
2+
Why do transition metals form coloured compounds
Ions formed with partially filled 3d subshell
Give examples of transition elements acting as catalysts
Hydrogenation Ni
Haber process Fe
Decomposition of h2o2 Mno2
Contact process v2o5
Give example of homogenous catalyst and why it occurs
Iron Catalyses thiosulphate and iodide reaction
Ions are both negetive so repel so high activation energy
Fe2+ is reacted with thiosulphate ions and are regenerated with I-
Define a complex ion
When one or more molecules or negetive ions bond datively to a central metal ion
Define ligand
Molecule or ion that donates a lone pair to a central metal ion forming dative bond
Define coordination number
Number of dative bonds to central metal ion
Prefix of chlorine ligand
Chloro
Prefix of cyanide ligand
Cyano
Prefix of hydroxide ligand
Hydroxo
Prefix of oxide ligand
Oxo
Prefix of water ligand
Aqua
Prefix of ammonia ligand
Ammine
Define mono and bidentate ligand
One or two lone pairs donated per molecule of ligand
Most common bidentate ligands
1,2-diaminoethane
Ethanedioate (oxaloacete ion)
Describe how oxygen is Transported using haemoglobin
Oxygen binds to iron ion ligand substitution with H2O or co2
Shape of complex ion with coordinationumber of 6
Octahedral
120 90
Shape of complex ion with coordinationumber of 4
Tetrahedral or Square planar
109.5 or 90
Shape of complex ion with coordinationumber of 2
Linear
180
What stereoisomerism can form in complex ions
Cis and trans
Optical in octahedral
Explain how platin complex ions can be used to treat cancer
Bind to DNA in cancer cells preventing cell growth
What colour are aqueous 2 +copper ions
Blue
In precipitation and ligand substitution reactions NH3 is used, how is it used in each.
Precipitation = Dilute and small volume = acts as base
Ligand substitution = excess conc NH3 = substitutes aqua ligands
Colour of tetra aqua dihydroxo copper precipitate
blue solid
Colour tetra ammine diaqua copper solution
Dark blue solution
Compared the size of chloro and aqua ligands and why it matters
Cl- larger than H2O
Only 4 Cl fit per 6 H2O
Colour of tetra chloro copper solution
Yellow
Colour of cr3+ aq
Violet
Green with h2so4
Colour tri aqua tri hydroxo chromium precipitate
Green grey
Colour hexa ammine chromium aq
Purple
How can you tell if a complex ion is a precipitate or solution
No charge = solid
Charged = aq
Which transition metal hydroxides. Are soluble in excess alkali
Chromium
Colour fe 2+ aq
Green
Colour fe(oh) 2 solid
Green
Colour fe3+
Yellow
Colour fe(oh) 3 solid
Orange brown precipitate
Colour tetra aqua di hydroxo iron solid
Green
Mn 2+ colour
Pink
Terta aqua di hydroxo manganese solid colour
Light brown
How many ethandioate surround a metal ion
3
How many EDTA fit around a metal ion
1
What can be used to oxidise iron, what colour change is observed
Manganese oxide ions
Purple to colourless
What can be used to reduce iron ions and what colour chnage is observed
Iodide ions
Yellow to pale green
Brown of iodine obscures change
What can be used to reduce cr2o7 2- ions to what
Zinc powder
To cr3+ and further to cr2+
Orange to green to pale blue
What can be used to oxidise cr3+ ions and what colour change is there
Hot alkaline hydrogen peroxide
Green to orange
What can be used to reduce copper ions (cu2+)
Colour change
Iodide ions
Pale blue to white precipitate (CuI)
Iodide is brown so obscures colour change
How can copper ions be disproportionated
Using hot Dilute sulphuric acid
