Actinium(III) hydroxide explained

Actinium(III) hydroxide is a white radioactive solid with the chemical formula of Ac(OH)₃.

Preparation

Actinium(III) hydroxide may be formed from soluble actinium salts and alkalis or ammonia water, and the resulting gel is precipitated as the product:^[1]

Ac³⁺ + 3 OH⁻ → Ac(OH)₃↓

Its solubility is slightly greater than that of lanthanum hydroxide, but it is still insoluble in water.

Chemical properties

Actinium(III) hydroxide is an alkaline hydroxide, it can react with acids to obtain actinium salts:

Ac(OH)₃ + 3 HNO₃ → Ac(NO₃)₃ + 3 H₂O

Notes and References

1. Tang, Renhuan; Liu, Yuanfang; Zhang, Qinglian; Zhang, Zhiyao. Series of Inorganic Chemistry. Volume 10. Actinides, Transactinides. 4.4 Actinium compounds. pp 75. (in Chinese)