NCHE321
Inorganic Chemistry
1.3.3 Properties of the 4d and 5d transition elements
Properties of metals
1.
Metals in the early groups
• Hard
• High melting points
2. Noble metals
• Soft
• Low melting points
3. Low reactivity – not affected by air/H2O at room temperature
4.
Cd attacked by acid
5.
6.
Most metals soluble in strong oxidising acid
– e.g. concentrated nitric acid
Nb and Ta slow soluble in warm concentrated alkaline solution
7.
Forming complexes driving force
Properties of the halides
1.
Metals higher OT’s than 3d-metals
2.
Lower OT’s – missing or unstable
3.
Fluorides – highest OT’s
4.
Later metals – above 3+ with effort
5.
Higher halides MX5 and MX6 undergo hydrolysis easier
6.
Lower halides – complex structure
• Dissolves in H2O or diluted acids
→ Polymeric species
Properties of the oxides
1.
Heavier metals (in comparison with 3d-metals) give higher
oxides
• More resistant against reduction
2.
Lower OT’s (2+ and 3+) only with higher groups
Properties in water
1.
Acid prevents hydrolysis
2.
Lower OT’s (2+ and 3+) of earlier groups oxidises easily
1.3.4
Reactions and properties of the 4f-elements
Lanthanides
– self study
https://youtu.be/xGhv39cEox0
https://youtu.be/uue-cwmdA2w
https://youtu.be/nYFmPYPWYfU
https://youtu.be/2oiNSkGOv8U
Properties
• Have a similar chemical and physical properties
• Silvery white, soft metals and shiny
• Tarnished easily when exposed to air
• Very reactive with most non-metals
• High melting and boiling point
Lanthanides reaction
• Oxidize rapidly in moist air
• Dissolve quickly in acids
• Reaction with oxygen is slow at room temperature, but they can ignite
around 150-200 °C
• React with halogens upon heating
• Upon heating, react with S, H, C and N
1.3.5
Reactions and properties of the 5f-elements
Actinides
– self study
https://youtu.be/jO8X3dRzSG0
https://youtu.be/HPJyMxU5oXU
https://youtu.be/apODDbgFFPI
https://youtu.be/fwtNvnWZjZY
https://youtu.be/YBNFvZ6Vr2U
https://youtu.be/hhUuFCrDOlw
https://youtu.be/tq6FDyFeCN0
Actinides Properties
•
•
•
•
Metals, soft, have a silvery color (but tarnish in air)
Relatively high density and plasticity.
Radioactive, paramagnetic
Pyrophoric, especially when finely divided (they spontaneously ignite
upon exposure to air).
Actinides Reactions
• Form halides with halogens at specific temperatures and trihalides
are the most well known halides
• All Actinides form oxides with different oxidation states