Molar mass 348.72 g/mol Formula Sm2O3 Appearance yellow-white crystals | Melting point 2,335 °C Density 8.35 g/cm³ | |
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Uses
Samarium(III) oxide is used in optical and infrared absorbing glass to absorb infrared radiation. Also, it is used as a neutron absorber in control rods for nuclear power reactors. The oxide catalyzes dehydration of acyclic primary alcohols to aldehydes and ketones. Another use involves preparation of other samarium salts.
Preparations
Samarium(III) oxide may be prepared by two methods:
1. thermal decomposition of samarium(III) carbonate, hydroxide, nitrate, oxalate or sulfate:
Sm2(CO3)3 → Sm2O3 + 3 CO22. by burning the metal in air or oxygen at a temperature above 150 °C:
4 Sm + 3 O2 → 2 Sm2O3Reactions
Samarium(III) oxide dissolves in mineral acids, forming salts upon evaporation and crystallization:
Sm2O3 + 6 HCl → 2 SmCl3 + 3 H2OThe oxide can be reduced to metallic samarium by heating with a reducing agent, such as hydrogen or carbon monoxide, at elevated temperatures.