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## Homework Statement:

- Using the Clausius-Clapeyron equation and the triple-point data of water, estimate the sublimation pressure of water at ##-30°C## and compare to the value in your Thermodynamic Tables (Cengel and Boles).

## Homework Equations:

- ##\int_1^2 (\frac {dP} P)_{sat}=\frac {\Delta h} {R} \int_1^2(\frac {dT} {T^2})_{sat}##

Before this question, the questions were about the Clapeyron equation, and how to estimate ##\Delta s##. I'm completely put off by this question however, and don't know where to start.

I've found that the triple point of water is at ##0.01°C##, and there is indeed data in the table for saturated water, for that temperature. So I know I've got this data available to me, but what next? I know also that sublimation is a state transition directly from a solid to a gas. How is sublimation linked to the triple point, and how do I manipulate this equation to find a single pressure?

After integration, the equation involves two pressures and two temperatures: what are states ##1## and ##2##, and in what state are we taking ##\Delta h## at?

I've found that the triple point of water is at ##0.01°C##, and there is indeed data in the table for saturated water, for that temperature. So I know I've got this data available to me, but what next? I know also that sublimation is a state transition directly from a solid to a gas. How is sublimation linked to the triple point, and how do I manipulate this equation to find a single pressure?

After integration, the equation involves two pressures and two temperatures: what are states ##1## and ##2##, and in what state are we taking ##\Delta h## at?