Question

At 310 K, the vapor pressures of substance B dissolved in liquid A are as follows:

xB 0.010 0.015 0.020

PB (kPa) 82.0 122.0 166.1

Show that the solution obeys Henry’s law in this range of concentrations, and calculate the Henry’s Law Constant at 310 K.

Answer 1

We may plot p_B vs X_B and look at the limiting slope by fitting the data to a low order polynomial. Such a plot is given below.

Since the data appears to closely fit a straight line we will use a linear fit to the data. Then

p_B = - 0.48 kPa + (8267. kPa) X_B

The Henry’s law constant is simply the slope of the line, so K_B = 8267. kPa.

another way solve above quation