Physical Properties of Ruthenium

Physical Properties of Ruthenium are related with its metallic structure. In the compact form ruthenium is a hard, brittle metal, resembling platinum in appearance and lustre. When powdered it has a dull grey colour. Its density varies greatly according to its physical condition, as is usually the case. After fusion, the value 12.063 has been obtained. Like palladium, ruthenium readily occludes gases, and when used as cathode in the electrolysis of acidulated water it absorbs the hydrogen, retaining it for a long time.

The specific heat of the powdered metal between 0° and 100° C. is 0.0611, and 0.0595 for the compact metal.

Ruthenium may be fused in the oxyhydrogen flame and distilled in the electric furnace, so that its melting- and boiling-points may be taken as of the order of 1900° C. and 2520° C. respectively.

The most intense lines in the spectrum of ruthenium are as follow:

Arc spectrum of ruthenium: 3417.50, 3428.50, 3436.87, 3499.09, 3593.18, 3596.31, 4080.78.

Spark spectrum of ruthenium: 2402.80, 2678.80, 2692.18, 2712.49, 2734.41, 2945.79, 2965.70, 2976.70, 3661.58, 3790.71, 3799.02, 3799.48, 4080.82, 4200.09, 4297.90, 4372.40, 4554.74.

Finely divided ruthenium acts as a catalyser, inducing, for example, the oxidation of alcohol to aldehyde and acetic acid in the presence of air.