Chapter 10, Problem 11RQ

1. 11. When liquid and vapor coexist in a container at equilibrium, the pressure is called vapor pressure. Several models predict vapor pressure. One, called the Antoine equation, first introduced by Ch. Antoine in 1888, yields vapor pressure in units of millimeters of mercury [mm Hg].

$P=10\left(A-\frac{B}{T+C}\right)$

The constants A, B , and C are called the Antoine constants; they depend on both fluid type and temperature. Note that B and C must be in the same units as temperature, and A is a dimensionless number, all determined by experiment.

Create a worksheet using the provided template. The Antoine constants, located in cells D17 to 124 of the workbook provided, should automatically fill in after the user selects one from a drop-down menu in cell A9 of the compounds shown below. (Hint: Use data validation and lookup expressions.)

Next, create a column of temperature (T) beginning at – 100 degrees Celsius and increasing in increments of 5 degrees Celsius until a temperature of 400 degrees Celsius.

In column B, calculate the vapor pressure (P, in millimeters of mercury, [mm Hg]) using the Antoine equation, formatted to four decimal places. If the equation is outside the valid temperature range for the compound, the pressure column should be blank.