- A 10.0 g sample of solid platinum is placed in a large, sealed vessel at a sufficiently low pressure that the platinum is able to sublimate directly to a gas. Some thermodynamic properties of platinum at low pressure are given in the following table.
Latent heat of sublimation, LS 363 kJ mol-1
Triple point pressure, pTP 3.50 Pa
Triple point temperature, TTP 1550'C
The platinum is heated at a rate of 10.0 W. If the initial temperature of the platinum is 25.0 ◦C, and it sublimates at the triple point temperature, how long will it take for the platinum to fully sublimate?
Q = nLS
Q = mCT[/B]
The Attempt at a Solution
My thoughts so far:
Time = Energy required/power
Energy required to sublimate at 1550"C = Q = nLS
Energy required to heat from 25 - 1550 = Q = mcΔT. This is where i have a problem as there is no data given for the specific heat capacity of platinum. I was considering using the dulong-petit rule that all solids have Cv = 3R but the volume is not kept constant so I'm not sure how to work out the energy required to heat the platinum.