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Glasse tellurium-containing

B. Determination of tellurium Procedure. The solution should contain not more than 0.2 g tellurium in 50 mL of 3M hydrochloric acid (ca 25 per cent by volume of hydrochloric acid). Heat to boiling, add 15 mL of a freshly prepared, saturated solution of sulphur dioxide, then 10 mL of a 15 per cent aqueous solution of hydrazinium chloride, and finally 25 mL more of the saturated solution of sulphur dioxide. Boil until the precipitate settles in an easily filterable form this should require not more than 5 minutes. Allow to settle, filter through a weighed filtering crucible (sintered-glass, or porcelain), and immediately wash with hot water until free from chloride. Finally wash with ethanol (to remove all water and prevent oxidation), and dry to constant weight at 105 °C. Weigh as Te. [Pg.466]

The presence of colloidal tellurium in glass produces a colour tint which varies from blue to brown according to the size of the colloid particles, the blue glass containing larger particles than the brown.3 Polytellurides are present in some coloured glasses and impart a colour which is red or violet-red. [Pg.356]

Glasses containing the chalcogenide elements, sulphur, selenium and tellurium. [Pg.465]

II. A Pyrex tube (12-mm. diameter) is torch-sealed at one end and is slightly constricted 10 cm. from the sealed end. The lower, sealed part of the tube is charged with tellurium, and a porcelain boat containing somewhat less than the calculated amount of aluminum powder is made to slide down into the tube until it is stopped by the constriction. A second constriction is then made at the open end. The tube is evacuated with an aspirator the aluminum is heated to a light red glow (caution, the glass may warp) and the tellurium melts. The evaporating tellurium reacts with the aluminum. A small fraction of the tellurium condenses on the colder walls above the aluminum. When all the tellurium has evaporated from the lower end of the tube, the latter is sealed and the condensed tellurium is evaporated from the walls and made to pass several times over the aluminum until its quantity appears to remain constant. [Pg.826]


See other pages where Glasse tellurium-containing is mentioned: [Pg.288]    [Pg.311]    [Pg.288]    [Pg.465]    [Pg.601]    [Pg.107]    [Pg.13]    [Pg.97]    [Pg.173]    [Pg.288]    [Pg.193]    [Pg.331]    [Pg.3]    [Pg.305]    [Pg.313]    [Pg.228]    [Pg.288]    [Pg.193]    [Pg.272]    [Pg.547]    [Pg.1]    [Pg.280]    [Pg.272]    [Pg.547]    [Pg.459]    [Pg.233]    [Pg.283]    [Pg.284]    [Pg.310]    [Pg.1192]    [Pg.1193]    [Pg.7]    [Pg.682]    [Pg.674]    [Pg.439]    [Pg.158]    [Pg.317]    [Pg.291]    [Pg.7]    [Pg.724]    [Pg.105]    [Pg.146]    [Pg.133]    [Pg.100]    [Pg.57]    [Pg.43]    [Pg.224]   
See also in sourсe #XX -- [ Pg.304 , Pg.601 ]




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