Question

What is the pressure of a gas at T = 227^oC, it is given that A = 5, B = 4 X 104 and C = 0 if T is in kelvin and p in mm Hg?

(a) 0.024 mm Hg

(b) 0.049 mm Hg

(c) 0.075 mm Hg

(d) 0.096 mm Hg

The question was asked in an interview for job.

Question is from Modeling and Predicting Vapor Pressure topic in chapter Real Gases: Equations of State, Single Component Two Phase Systems, Saturation & Condensation of Basic Chemical Engineering

Answer 1

The correct option is (b) 0.049 mm Hg

To explain: ln p* = A – B/(C + T), => ln p = 5 – 4 X 10^3/(273 +227) = -3, => p = 0.049 mm Hg.