Calculate the critical density of methyl alcohol?

Question

Calculate the critical density of methyl alcohol from the following data:
ρ -------- d liq. (g/cc) ------ d vap. (g/cc)
13.57 ------ 0.6495 ----------- 0.01562
61.25 ------ 0.4675 ----------- 0.1003
The critical temperature is 240 C.

Calculate the critical density of methyl alcohol from the following data:
t (0C) ρ (atm) d liq. (g/cc) d vap. (g/cc)
150 13.57 0.6495 0.01562
225 61.25 0.4675 0.1003
The critical temperature is 240 C.

Answer 1

Are the numbers in the first column temperatures?
Are all the data given at 1 atm?

If so, fit each set of data to an equation...
For liquids, this is rho=A(1-T/Tcrit)^D, T and Tcrit should be in kelvins, rho should be in mol/L (you can convert back later).

For gases, the van der Waals eq. is good for this.
P=RT/(1/rho-b)-a(rho)^2

(Answer given by ideal gas law can have error >100%, but it's always a good rough estimate).

Answer 2

Methyl Alcohol Density

Answer 3

Use P = dRT