General Properties Of The Transition Elements
Chapter Name : The D- And F- Block Elements |
Sub Topic Code : 102_12_08_03_06 |
Topic Name : General Properties Of The Transition Elements |
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Sub Topic Name : Trends In Stability Of Higher Oxidation States |
|
Introduction
•
The highest oxidation numbers are achieved in TiX4,VF5
and CrF6
•
The +7 state for Mn is not represented in simple
halides but MnO3F is known, and beyond Mn no metal has a trihalide
except FeX3 and CoF3.
• The ability of fluorine to stabilise the
highest oxidation state is due to either higher lattice energy as in the case
of CoF3, or higher bond enthalpy terms for the higher covalent
compounds, e.g., VF5 and CrF6.
• Another feature of fluorides is their
instability in the low oxidation states e.g., VX2 (X = CI, Br or I)
and the same applies to CuX.
• The ability of oxygen to stabilise the highest
oxidation state is demonstrated in the oxides.
The highest oxidation
number in the oxides coincides with the group number and is attained in Sc2O3
to Mn2O7.
Pre-Requisites:
Periodic table, elements
Activity:
Various precious metals such as silver, gold and
platinum are industrially important
Real Life Question:
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Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Group | Group is the vertical column on the periodic table which contains elements having the similar properties |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Gold ring Iron Rod | Transition metals like gold and iron are tough solids at room temperature |
Real life uses :
To make jewellery, utensils
Places to visit :
Bank, jewellery shop
Practical examples around us
| Examples | Explainations |
|---|---|
| Gold coins | • Various precious metals such as silver, gold and platinum and industrially important |
What you learn in Theory:
•
The highest oxidation numbers are achieved in TiX4,VF5
and CrF6
•
The +7 state for Mn is not represented in simple
halides but MnO3F is known, and beyond Mn no metal has a trihalide
except FeX3 and CoF3.
• The ability of fluorine to stabilise the
highest oxidation state is due to either higher lattice energy as in the case
of CoF3, or higher bond enthalpy terms for the higher covalent
compounds, e.g., VF5 and CrF6.
• Another feature of fluorides is their
instability in the low oxidation states e.g., VX2 (X = CI, Br or I)
and the same applies to CuX.
• The ability of oxygen to stabilise the highest
oxidation state is demonstrated in the oxides.
The highest oxidation
number in the oxides coincides with the group number and is attained in Sc2O3
to Mn2O7.
What you learn in Practice:
•
The highest oxidation numbers are achieved in TiX4,VF5
and CrF6
•
The +7 state for Mn is not represented in simple
halides but MnO3F is known, and beyond Mn no metal has a trihalide
except FeX3 and CoF3.
• The ability of fluorine to stabilise the
highest oxidation state is due to either higher lattice energy as in the case
of CoF3, or higher bond enthalpy terms for the higher covalent
compounds, e.g., VF5 and CrF6.
• Another feature of fluorides is their
instability in the low oxidation states e.g., VX2 (X = CI, Br or I)
and the same applies to CuX.
• The ability of oxygen to stabilise the highest
oxidation state is demonstrated in the oxides.
The highest oxidation
number in the oxides coincides with the group number and is attained in Sc2O3
to Mn2O7.