Trusted by Students Everywhere
Why Choose Us?
0% AI Guarantee

Human-written only.

24/7 Support

Anytime, anywhere.

Plagiarism Free

100% Original.

Expert Tutors

Masters & PhDs.

100% Confidential

Your privacy matters.

On-Time Delivery

Never miss a deadline.

dP/dT = L/T deltaV, is a differential equation that can, in principle, be solved to find the shape of the entire phase-boundary curve

Physics Sep 29, 2020

dP/dT = L/T deltaV,

is a differential equation that can, in principle, be solved to find the shape of the entire phase-boundary curve. To solve it, however, you have to know how both L and deltaV depend on temperature and pressure. Often, over a reasonably small section of the curve, you can take L to be constant. Moreover, if one of the phases is a gas, you can usually neglect the volume of the condensed phase and just take deltaV to be the volume of the gas, expressed in terms of temperature and pressure using the ideal gas law. Making all these assumptions, solve the differential equation explicitly to obtain the following formula for the phase boundary curve:

P = (constant) x e-L/RT (the vapor pressure equation).

Expert Solution

dP/dT = L/{T* del(V)}
If del(V) = V, then,
dP/dT = [L/(T*V)] ----(1)
From ideal gas law, PV = RT
Hence, V = (RT)/P
Substitute this V in eq. (1) and we get,

dP/dT = (L/T)*(P/RT) = LP/(R*T^2)
Hence, dP/P = (L/R)*dT/(T^2)
Integrate both sides and we get,

ln P = (L/R)*(-1/T) + c, where c is a constant

Hence P = e^[-(L/RT)+c] = e^c * e^[-(L/RT)]
or, P = constant * e^[-L/RT)] QED

Archived Solution
Unlocked Solution

You have full access to this solution. To save a copy with all formatting and attachments, use the button below.

Already a member? Sign In
Important Note: This solution is from our archive and has been purchased by others. Submitting it as-is may trigger plagiarism detection. Use it for reference only.

For ready-to-submit work, please order a fresh solution below.

Or get 100% fresh solution
Get Custom Quote
Secure Payment