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CH 316 Special Topics in Inorganic
Chemistry
Transition Elements,
Lanthanides, Actinides, Rare
Earth Elements and its
Application and Extraction
Dr Chamara Jayasundera Department of Chemistry, Faculty of Science
University of Peradeniya, Kandy, Sri Lanka
E Mail:- [email protected]
What :- Module CH 316
Title:- Chemistry of Transition Elements,
Lanthanide, Actinides, Rare Earth: Chemistry
and Extraction
When :- Friday 13.00 pm-14.00 pm
Where :- New Chemistry Lecture Theatre
Who :- Dr Chamara Jayasundera
Why :- To gain a knowledge and
understanding of Transition Elements,
Lanthanides and Actinides
Assessments:- Applications of Transition
Elements and/or Lanthanides and/or Actinides
The Transition Metals, the
Lanthanides and the Actinides
The Metals in the Middle
• Groups 3-12 are called the transition elements.
• All of them are metals.
• Across any period from Group 3 through 12, the properties of the elements change less noticeably than they do across a period of representative elements.
• Most transition elements are found combined with other elements in ores.
Properties – catalysis
• A catalyst is a substance that speeds up a
chemical reaction without being used up.
• Catalysts are hugely valuable in industry
where they can save time and energy.
• Many transition elements ( and their
compounds) are catalysts.
V
Ti
Used in plastic
manufacture
Fe
Ni
Used in oil
hydrogenation
Uses The three most commonly known transition
elements are iron or steel, copper and zinc.
iron or
steel
General
engineering
metal
copper
Electrical and
plumbing work
zinc
Galvanising steel
to protect it
20_435
0.2
Ato
mic
ra
dii
(nm
)
Atomic number
La
Hf
Ta
WRe Os
Ir Pt
Au
Zr
Y
NbMo
Tc Ru
Rh Pd
Ag
Sc
Ti
VCr
Mn Fe Co NiCu
1st series (3d)
2nd series (4d)
3rd series (5d)
0.1
0.15
Multiple Oxidation States
Metallic Behavior/Reducing Strength
• Lower oxidation state = more metallic
Color and Magnetism
• e- in partially filled d sublevel absorbs visible light
• moves to slightly higher energy d orbital
Magnetic properties due to unpaired electrons
Electronegativity increases down column
Uses of Transition Elements
• Chromium’s name comes from the Greek word for color, chrome.
• Many other transition elements combine to form substances with brilliant colors.
Chromium Chemical properties reflect oxidation state
Valence-State Electronegativity
Electronegativity, EN:
electron “pulling power”
Valence-state EN:
metal in higher oxidation state
is more positive
has stronger pull on electrons
is more electronegative
“Effective EN”