Calculate the Temperature and Pressure of a melting point

AI Thread Summary
The discussion focuses on calculating the temperature and pressure at the melting point using the adiabatic process, where Tds=0. Participants emphasize the importance of the derivative of pressure with respect to temperature at constant entropy, along with the slope of the fusion curve, which intersects at 0°C under 1 atm. There is a debate on whether to assume the partial derivative of pressure with respect to temperature remains constant or if the specific volume of ice should be constant for graphing pressure versus temperature in the solid phase. The consensus suggests assuming a constant partial derivative for the calculations. This approach will aid in accurately determining the relationship between pressure and temperature during the melting process.
romanski007
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Homework Statement
Ice is initially at -3C and 1atm. The pressure is increased adiabaticallu until the ice reaches the melting point. At waht temperature and pressure is this melting point? (Hint: At what point does a line whose slope is (dP/dT)_s cut a line whose slope is that of the fusion curve, -1.35 x 10^7 Pa / K?)
Relevant Equations
(dP/dT)_s = c_p / (Tv \beta) , c_p = 2.01 kJ / kg K, v = 1.09 x 10^-3 m^3 / kg and beta = 1.58 x 10^-4 / K
Adiabatic increase in pressure implies Tds=0, can someone tell me how to proceed?
 
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The problem statement gives you the equation for the derivative of P with respect to T at constant s, together with all the parameters you need to calculate it. You also have the equation for the slope of the fusion curve, and you know that, at 1 atm, the fusion curve passes through 0 C.
 
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Chestermiller said:
The problem statement gives you the equation for the derivative of P with respect to T at constant s, together with all the parameters you need to calculate it. You also have the equation for the slope of the fusion curve, and you know that, at 1 atm, the fusion curve passes through 0 C.
Chestermiller said:
The problem statement gives you the equation for the derivative of P with respect to T at constant s, together with all the parameters you need to calculate it. You also have the equation for the slope of the fusion curve, and you know that, at 1 atm, the fusion curve passes through 0 C.

Should I assume that the partial derivative of P wrt T remains constant throughout the process or that the specific volume of ice remains constant to work out the graph of P vs T for solid phase? Thanks.
 
romanski007 said:
Should I assume that the partial derivative of P wrt T remains constant throughout the process or that the specific volume of ice remains constant to work out the graph of P vs T for solid phase? Thanks.
Assume constant partial derivative.
 
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