Dynamic viscosity of liquid rubidium at different temperatures

Dynamic viscosity of liquid rubidium at different temperatures

Junjie Chen

Department of Energy and Power Engineering, School of Mechanical and Power Engineering, Henan Polytechnic University, 2000 Century Avenue, Jiaozuo, Henan, 454000, P.R. China

Contributor: Junjie Chen, ORCID: 0000-0001-5055-4309, E-mail address: [e-mail]

Rubidium is the second most reactive metal and is very soft, with a silvery-white lustre. Rubidium and cesium often occur together in nature. Rubidium, however, is more widely scattered and seldom forms a natural mineral; it is found only as an impurity in other minerals, ranging in content up to 5 percent in such minerals as lepidolite, pollucite, and carnallite. Brine samples have also been analyzed that contain up to 6 parts per million of rubidium. In the principal commercial process of rubidium production, small amounts of rubidium are obtained from the mixture of alkali metal carbonates remaining after lithium salts are extracted from lepidolite. Primarily a potassium carbonate, this by-product also contains approximately 23 percent rubidium and 3 percent cesium carbonates. The primary difficulty associated with the production of pure rubidium is that it is always found together with cesium in nature and is also mixed with other alkali metals. Because these elements are very similar chemically, their separation presented numerous problems before the advent of ion-exchange methods and ion-specific complexing agents such as crown ethers. Once pure salts have been prepared, it is a straightforward task to convert them to the free metal. This can be done by electrolysis of the fused cyanide or by reduction with calcium or sodium followed by fractional distillation. Rubidium is difficult to handle because it ignites spontaneously in air, and it reacts violently with water to yield a solution of rubidium hydroxide and hydrogen, which bursts into flames. If a metal sample has a large enough surface area, it can burn to form superoxides. Rubidium superoxide is a yellow powder. Rubidium peroxides can be formed by oxidation of the metal with the required amount of oxygen. Rubidium forms two other oxides. Rubidium and cesium are miscible in all proportions and have complete solid solubility.

Temperature (degrees Celsius), Dynamic viscosity (grams per meter per second)

50                               0.542

100                             0.435

150                             0.365

200                             0.316

250                             0.28

300                             0.252

350                             0.23

400                             0.212

450                             0.197

500                             0.185

550                             0.174

600                             0.165

650                             0.157

700                             0.15

750                             0.143

800                             0.138

850                             0.133

900                             0.128

950                             0.124

1000                                  0.12

1050                                  0.117

1100                                  0.114

1150                                  0.111

1200                                  0.108

1250                                  0.105

1300                                  0.103

1350                                  0.101

1400                                  0.099

1450                                  0.097

1500                                  0.095

1550                                  0.093

1600                                  0.092

1650                                  0.09

Contributor: Junjie Chen, ORCID: 0000-0001-5055-4309, E-mail address: [e-mail], Department of Energy and Power Engineering, School of Mechanical and Power Engineering, Henan Polytechnic University, 2000 Century Avenue, Jiaozuo, Henan, 454000, P.R. China