Lanthanum (III) oxide

Lanthanum oxide
Lanthanum oxide
Are common
Systematic ; name	Lanthanum oxide
Traditional names	Lanthanum Sesquioxide
Chem. formula	La 2 o 3
Physical properties
condition	colorless (white) crystals
Molar mass	325.81 g / mol
Density	6.51; 6.57 g / cm³
Thermal properties
T. melt.	2280; 2313; 2317; 2320 ° C
T. bale.	≈4200; 4197 ° C
Like heat resistant.	108.8 J / (molK)
Enthalpy of Education	-1794.2 kJ / mol
Chemical properties
Solubility in water	0,0004 g / 100 ml
Classification
Reg. CAS number	1312-81-8
PubChem
Reg. EINECS number
Smiles
Inchi
RTECS	OE5330000
ChemSpider
Security
NFPA 704	0 one one

Lanthanum (III) oxide is a binary inorganic compound of lanthanum metal and oxygen with the formula La ₂ O ₃ , colorless (white) crystals, insoluble in water.

Getting

Burning of metallic lanthanum in air:

{\mathsf {4La+3O_{2}\ {\xrightarrow {450^{o}C}}\ 2La_{2}O_{3}}}

{\ displaystyle {\ mathsf {4La + 3O_ {2} \ {\ xrightarrow {450 ^ {o} C}} \ 2La_ {2} O_ {3}}}}

{\mathsf {4La+3O_{2}\ {\xrightarrow {450^{o}C}}\ 2La_{2}O_{3}}}

Decomposition of lanthanum hydroxide , nitrate , sulfate , carbonate or oxalate :

{\mathsf {2La(OH)_{3}\ {\xrightarrow {300-1100^{o}C}}\ La_{2}O_{3}+3H_{2}O}}

{\ displaystyle {\ mathsf {2La (OH) _ {3} \ {\ xrightarrow {300-1100 ^ {o} C}} \ La_ {2} O_ {3} + 3H_ {2} O}}}

{\mathsf {2La(OH)_{3}\ {\xrightarrow {300-1100^{o}C}}\ La_{2}O_{3}+3H_{2}O}}

{\mathsf {4La(NO_{3})_{3}\ {\xrightarrow {780^{o}C}}\ 2La_{2}O_{3}+12NO_{2}+3O_{2}}}

{\ displaystyle {\ mathsf {4La (NO_ {3}) _ {3} \ {\ xrightarrow {780 ^ {o} C}} \ 2La_ {2} O_ {3} + 12NO_ {2} + 3O_ {2} }}}

{\mathsf {4La(NO_{3})_{3}\ {\xrightarrow {780^{o}C}}\ 2La_{2}O_{3}+12NO_{2}+3O_{2}}}

{\mathsf {2La_{2}(SO_{4})_{3}\ {\xrightarrow {1150-1200^{o}C}}\ 2La_{2}O_{3}+6SO_{2}+3O_{2}}}

{\ displaystyle {\ mathsf {2La_ {2} (SO_ {4}) _ {3} \ {\ xrightarrow {1150-1200 ^ {o} C}} \ 2La_ {2} O_ {3} + 6SO_ {2} + 3O_ {2}}}}

{\mathsf {2La_{2}(SO_{4})_{3}\ {\xrightarrow {1150-1200^{o}C}}\ 2La_{2}O_{3}+6SO_{2}+3O_{2}}}

{\mathsf {La_{2}(CO_{3})_{3}\ {\xrightarrow {900-1000^{o}C}}\ La_{2}O_{3}+3CO_{2}}}

{\ displaystyle {\ mathsf {La_ {2} (CO_ {3}) _ {3} \ {\ xrightarrow {900-1000 ^ {o} C}} \ La_ {2} O_ {3} + 3CO_ {2} }}}

{\mathsf {La_{2}(CO_{3})_{3}\ {\xrightarrow {900-1000^{o}C}}\ La_{2}O_{3}+3CO_{2}}}

{\mathsf {La_{2}(C_{2}O_{4})_{3}\ {\xrightarrow {800^{o}C}}\ La_{2}O_{3}+3CO_{2}+3CO}}

{\ displaystyle {\ mathsf {La_ {2} (C_ {2} O_ {4}) _ {3} \ {\ xrightarrow {800 ^ {o} C}} \ La_ {2} O_ {3} + 3CO_ { 2} + 3CO}}}

{\mathsf {La_{2}(C_{2}O_{4})_{3}\ {\xrightarrow {800^{o}C}}\ La_{2}O_{3}+3CO_{2}+3CO}}

Lanthanum sulfide oxidation:

{\mathsf {2La_{2}S_{3}+9O_{2}\ {\xrightarrow {700^{o}C}}\ 2La_{2}O_{3}+6SO_{2}}}

{\ displaystyle {\ mathsf {2La_ {2} S_ {3} + 9O_ {2} \ {\ xrightarrow {700 ^ {o} C}} \ 2La_ {2} O_ {3} + 6SO_ {2}}}}

{\mathsf {2La_{2}S_{3}+9O_{2}\ {\xrightarrow {700^{o}C}}\ 2La_{2}O_{3}+6SO_{2}}}

Physical Properties

Lanthanum (III) oxide forms colorless (white) crystals of several crystalline modifications:

A- La ₂ O ₃ - hexagonal syngony , space group P 3 m1 , cell parameters a = 0.39373 nm, c = 0.61299 nm, Z = 1, exists at temperatures up to 2040 ° C.
H- La ₂ O ₃ - hexagonal syngony , exists at a temperature of 2040-2110 ° C.
X- La ₂ O ₃ - cubic syngony , space group I a3 , cell parameters a = 1.14 nm, Z = 16, exists at a temperature of 2100-2313 ° C.

Chemical Properties

Reacts with acids :

{\mathsf {La_{2}O_{3}+6HCl\ {\xrightarrow {}}\ 2LaCl_{3}+3H_{2}O}}

{\ displaystyle {\ mathsf {La_ {2} O_ {3} + 6HCl \ {\ xrightarrow {}} \ 2LaCl_ {3} + 3H_ {2} O}}}

It absorbs carbon dioxide from the air with the formation of basic carbonate :

{\mathsf {La_{2}O_{3}+2CO_{2}+H_{2}O\ {\xrightarrow {}}\ 2LaCO_{3}(OH)}}

{\ displaystyle {\ mathsf {La_ {2} O_ {3} + 2CO_ {2} + H_ {2} O \ {\ xrightarrow {}} \ 2LaCO_ {3} (OH)}}}

When heated in the presence of reducing agents, it reacts with gaseous hydrogen sulfide :

{\mathsf {La_{2}O_{3}+3H_{2}S+3C\ {\xrightarrow {1000^{o}C}}\ La_{2}S_{3}+3CO+3H_{2}}}

{\ displaystyle {\ mathsf {La_ {2} O_ {3} + 3H_ {2} S + 3C \ {\ xrightarrow {1000 ^ {o} C}} \ La_ {2} S_ {3} + 3CO + 3H_ { 2}}}}

In the presence of reducing agents, reacts with chlorine :

{\mathsf {La_{2}O_{3}+3Cl_{2}+3C\ {\xrightarrow {800-900^{o}C}}\ 2LaCl_{3}+3CO}}

{\ displaystyle {\ mathsf {La_ {2} O_ {3} + 3Cl_ {2} + 3C \ {\ xrightarrow {800-900 ^ {o} C}} \ 2LaCl_ {3} + 3CO}}}

Application

Component of special glasses.
High temperature ceramics.
An intermediate in the production of lanthanum fluoride .

Literature

Chemical Encyclopedia / Editorial Board: Knunyants I.L. et al. - M .: Soviet Encyclopedia, 1990. - T. 2. - 671 p. - ISBN 5-82270-035-5 .
Chemistry Handbook / Editorial: Nikolsky B.P. et al. - 2nd ed., rev. - M.-L.: Chemistry, 1966. - T. 1. - 1072 p.
Chemistry Handbook / Editorial: Nikolsky B.P. et al. - 3rd ed., rev. - L .: Chemistry, 1971. - T. 2. - 1168 p.
Lidin R.A. and other Chemical properties of inorganic substances: Textbook. manual for universities. - 3rd ed., Rev. - M .: Chemistry, 2000 .-- 480 p. - ISBN 5-7245-1163-0 .
Ripan R., Chetyanu I. Inorganic chemistry. Chemistry of metals. - M .: Mir, 1972. - T. 2. - 871 p.