Lanthanum is a
malleable, ductile, soft, silvery white metallic element belonging to group number 3 of periodic table; atomic number 57; atomic mass 138.91;
melting point 920°C; boiling point 3464°C; specific gravity 6.162
g/cm3; Oxidation state
3; electronic configuration [Xe] 5d1 6s2. It oxidizes rapidly when exposed to moisture
air. Lanthanum
is the second most abundant
rare-earth element next to cerium. Lanthanide (or lanthanoid) series are the group of rare-earth elements from
lanthanum (atomic
numbers 57) to 71; their chemical properties are similar to each other. The chemical properties
of scandium and yttrium are also similar to the lanthanides;
these group are often referred to "rare earth elements".
Atomic
No.
|
Element
|
Symbol
|
CAS
RN
|
21 |
Scandium |
Sc
| 7440-20-2 |
39 |
Yttrium |
Y
| 7440-65-5 |
57 |
Lanthanum |
La | 7439-91-0 |
58 |
Cerium |
Ce | 7440-45-1 |
59 |
Praseodymium |
Pr | 7440-10-0 |
60 |
Neodymium |
Nd | 7440-00-8 |
61 |
Promethium |
Pm | 7440-12-2 |
62 |
Samarium |
Sm | 7440-19-9 |
63 |
Europium |
Eu | 7440-53-1 |
64 |
Gadolinium |
Gd | 7440-54-2 |
65 |
Terbium |
Tb | 7440-27-9 |
66 |
Dysprosium |
Dy | 7429-91-6 |
67 |
Holmium |
Ho | 7440-60-0 |
68 |
Erbium |
Er | 7440-52-0 |
69 |
Thulium |
Tm | 7440-30-4 |
70 |
Ytterbium |
Yb | 7440-64-4 |
71 |
7440-64-4 |
Lu | 7440-64-4 |
Lanthanum
belongs to the group of transition metal whose atom has an incomplete d sub-shell, or which can give rise to
cations with an incomplete d sub-shell; includes elements
21 through 29 (scandium through copper), 39 through 47 (yttrium through silver),
57 through 79 (lanthanum through gold), and all
elements from 89 (actinium). Minerals which incorporates lanthanum
include lanthanite,
cordylite, parisite,
bastnaesite, synchysite, and monazite. Lanthanum
is a major component of misch metal, a pyrophoric alloy used in
lighter flints. Small amounts of lanthanum added to steel or iron to improves ductility
and to produce nodular cast
iron. Rare-earth compounds containing lanthanum are used in carbon
lighting applications. Lanthanum is used to replace
lime in calcium lights and in optical glass for the alkali resistance, the high refractive
index and low dispersion applications. Lanthanum-rich lanthanide compounds are
used in cracking
reactions as a FCC catalyst. Lanthanum nitrate
is a hygroscopic white crystals; melting point 40
C. It is soluble in water and alcohol. It is used as an antiseptic
and a catalyst.
It is used in gas mantles, specialty glass and water treatment. Lanthanum oxide,
also called lanthana; lanthanum sesquioxide; lanthanum trioxide,
is a white powder melting point 2000 C. It is insoluble
in water but soluble in acids. Lanthanum Oxide
is used in manufacturing high transparency and refraction index
glass. The end application
is precision optics like microscope and telescope
lenses and camera components. It is used in preparing
special glasses. Lanthanum sulfate is
a white crystals. It is slightly soluble in water, soluble in
alcohol. It is used for atomic weight determinations for lanthanum. Lanthanum
carbonate is a hygroscopic powder soluble in water and acids.
It is a component of the catalyst used in cracking reactions.
In
medicinal use, lanthanum carbonate is used in the treatment of hyperphosphataemia in patients with end stage renal disease. Examples
of lanthanum salts include:
- Lanthanum
acetate La(O2C2H3)3
(CAS RN: 917-70-4)
- Lanthanum
boride (LaB6)
(CAS RN: 12008-21-8)
- Lanthanum bromide
(LaBr3) (CAS RN: 13536-79-3)
- Lanthanum carbide
(LaC2) (CAS RN: 12071-15-7)
- Lanthanum carbonate
La2(CO3)3
(CAS RN: 587-26-8)
- Lanthanum chloride
LaCl3
(CAS RN: 10099-58-8)
- Lanthanum edetate
(CAS RN: 11138-87-7)
- Lanthanum
fluoride LaF3 (CAS RN: 13709-38-1)
- Lanthanum hydride
(LaH3) (CAS RN: 13864-01-2)
- Lanthanum hydroxide
(La(OH)3) (CAS RN: 14507-19-8)
- Lanthanum iodide
(LaI3) (CAS RN: 13813-22-4)
- Lanthanum
nitrate
La(NO3)3
(CAS RN: 35099-99-1)
- Lanthanum nitride
(LaN) (CAS RN: 25764-10-7)
- Lanthanum oxalate La2(C2O4)3
(CAS RN: 537-03-1)
- Lanthanum oxide La2O3 (CAS RN: 1312-81-8)
- Lanthanum oxide sulfide
(La2O2S) (CAS RN: 12031-43-5)
- Lanthanum oxybromide
(CAS RN: 13875-40-6)
- Lanthanum silicide
(LaSi2) (CAS RN: 12056-90-5)
- Lanthanum sulfate La2(SO4)3
(CAS RN: 10099-60-2)
- Lanthanum sulfide
(La2S3) (CAS RN: 12031-49-1)
- Lanthanum titanium oxide
(La2Ti2O7) (CAS RN: 12031-47-9)
- Lanthanum tribromate
(CAS RN: 28958-23-8)
- Lanthanum(III)
phosphate (CAS RN: 14913-14-5)
- Chromium lanthanum oxide
(CrLaO3) (CAS RN: 12017-94-6)
|