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Flashcards in General Deck (26)
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What are transition metals?

These are metals that have partially filled d orbitals or form ions with partially filled d orbitals


What is pairing energy?

The energy required to place 2 electrons in one orbital. This requires energy as this causes repulsions.


Describe the order of occupation of orbitals

1s, 2s, 2p, 3s, 3p, 4s, 3d 4p

The 3d orbital is higher in energy than the 4s orbital
4s is filled first and empties first


What energy to the 3d orbitals have in relation to each other?

They are degenerate
This means they all have the same energy


Which elements do not follow the filling orbital rules?

Cr has the electron configuration: 3d54s1
Cu has the electron configuration: 3d104s1

One of the s electrons have moved into the d orbitals
This is because this maximise angular momentum and avoids repulsions in the 4s orbital from pairing energy


What are the 5 d orbitals?

dyz, dxy, dxz, dz2 and dx2-y2


Why are d orbitals bad at shielding?

They are bad at shielding valence electrons due to their shape


Why is Zn not considered a transition metal?

Zn and Zn2+ both have d10 configuration which means it's d orbitals are completely filled
Therefore it is not considered a transition metal


Describe the trend in ionisation energy

Increase from Ca to Cr (d1-d4) as an electron is removed from singly occupied orbitals
Decrease at Mn (d5) as electron has been removed from doubly occupied orbital
Increase from d6-d10


Why is there a difference in energy between d1-d5 and d6-d10

There is a difference in energy due to pairing energy


Why are doubly occupied orbitals easier to remove from?

The electrons in doubly filled orbitals will experience repulsions and so less energy is required to remove them


Describe the trend in atomic radius

The atomic radius from Li-F decreases due to increase in zeff
Anomalous increase at Mn- double filled orbital as repulsion are more significant than zeff therefore radius increases


Describe the trend in orbital size

As n increases, orbital size increases


What is the lanthanide contraction?

D orbitals are poor at shielding so they cause anomalous trends in atomic orbital size


What is a metal complex?

This is a Lewis acid which acts as a central metal ion with a number of Lewis bases which are the ligands


What is a donor atom?

This is the atom in the ligand that forms the bond to the central metal atom by donation of a pair of electrons


What is coordination number?

This is the number of ligand donor atoms to which the central metal atom is directly bonded


Describe the elemental abundances in the earths crust, the sea, and the human body

Earths crust- lots of Fe
Sea water- even distribution
Human body- lots of transition metals- higher conc- as many TM are biologically necessary


Describe the applications of transition metals

- structural materials- Fe alloyed with Cr, V, MO, Ni, Ti
- electrical conductors- cu
- Batteries- MnO2, Ni, Zn
- magnetic materials- Fe+, Co, Ni, Fe2O3 or CrO2
Catalyst- Co, Cu


What is a chelate?

A complex containing a polydentate ligand is called a chelate


What is a chelating ligand?

Polydentate ligands are collectively known as chelating ligands


What factors determine coordinating number?

1) The size of the central atom (large means more ligands)

2) the steric interactions between the ligands

3) the electronic interactions


What charge can coordination complexes have ?

They can be neutral or a salt


What charge can ligands have?

They can be neutral or anionic


How do you write the formula of a complex?

Formula in square brackets
Metal ion first then anionic ligands and then neutral ligands
Cations come before anions


How do you name a complex?

Ligands in alphabetical order
Then name of central atom with charge of complex
Prefix is number of ligands
Stereochemical descriptors at the start
Anionic complexes end in ate