U1-3 - Transition Metals Flashcards
Which two transition metals are exceptions to the Aufbau principle?
Chromium, [Ar] 4s1 3d5
Copper, [Ar] 4s1 3d10
Why do chromium and copper adopt 3d5 and 3d10 configurations?
Special stability associated with half-filled and full 3d subshell.
Which electrons are lost first when transition metals form ions?
4s electrons
Why is valency 2 common in transition metals?
Loss of two 4s electrons.
Oxidation state/number
Valency equivalent. Can include charge.
E.g. II, +2, 2 all the same.
Oxidation state of oxygen
–2
Oxidation state of halogens
–1
Oxidation state of group 1 metals
+1
How can you predict if an oxidation state is stable?
If its electronic configuration is stable, the oxidation state is also stable.
Oxidation can be defined as an ___________ in oxidation number.
increase
(e.g. +2 to +3)
Reduction can be considered as a ___________ in oxidation number.
decrease
(e.g. +2 to 0)
Compounds with metals in _______ oxidation states tend to be oxidising agents.
high
(e.g. +5)
Compounds with metals in high oxidation states tend to be __________ agents.
oxidising
Compounds with metals in _____ oxidation states tend to be reducing agents.
low
(e.g. +2)
Compounds with metals in low oxidation states tend to be __________ agents.
reducing
Ligand
A negative ion or molecule with non-bonding
e− pairs that they donate to the central metal atom or ion.
What type of bonds are formed between ligands and metals?
Dative (covalent)
Denticity
No. of e− pairs a ligand can donate to the central metal ion.
Monodentate ligands donate _________.
1 e− pair
List as many monodentate ligands as you can.
H2O, NH3, CN−, halide ions, nitrite (NO2−), OH−.
(In general, charge of 1− or has 1 atom with non-bonding pairs.)
Bidentate ligands donate _________.
2 e− pairs
Name two bidentate ligands.
oxalate and ethylenediamine (en)