- #1

romanski007

- 12

- 1

- Homework Statement
- A substance has isothermal compressibility kappa = (aT^3)/(P^2) and an expansivity beta = (bT^2)/P where a and b are constants.

i) find the equations of state of the substance and the ratio a/b.

- Relevant Equations
- kappa = (aT^3)/(P^2)

beta = (bT^2)/P

Starting from v(P,T),

dv=(dv/dp)_T dp + (dv/dT)_P dt

i implemented conditions when T and P are constant and ended up with

ln V = aT^3/P + constant and ln V = bT^3 /3P + constant

If i assume that the constant is 0, i can say that a/b = 1/3 but how do i justify this assumption?

dv=(dv/dp)_T dp + (dv/dT)_P dt

i implemented conditions when T and P are constant and ended up with

ln V = aT^3/P + constant and ln V = bT^3 /3P + constant

If i assume that the constant is 0, i can say that a/b = 1/3 but how do i justify this assumption?