Vapor Pressure and Heat of Sublimation of Tungsten
نویسنده
چکیده
The va por press ure of tungs te n was measured by the Langmuir method in the te mpe rature range 2600 to 3100 K using a vac uum microbala nce. Four se ries of data gave concorda nt result s and three of the fo ur seri es gave second and third law heats of s ublimation in exce llent agreeme nt. A va por pressure equ ation representing the data is log P(atm )=45385/T + 7.87 1, based on our mean third la w heat a nd ta bulated en tropies at 2800 K. The mean third law heat of s ublim ation al 298.15 K is 205.52 ± 1.1 kcal molI (859.90 ± 4.6 kJ molI) where the uncertai nty is an overall estimated error. Rates of va porization are about 1/2 those pre viously acce pted for tungste n.
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