In a high temperature corrosion cell we have 5 vol% O2 and 500 vppm HCl. We know at high temperature the reaction is Deacon Process (600C) 4HCl(g)+O2(g)=2Cl2(g)+2H2O(g). We have thermodynamic phase diagram of a system (e.g., Fe-O2-Cl2) at 600 (log pO2 - x axis and log pCl2 in Y axis). How do we calculate the PCl2 and PO2 from the available data. Many thanks.

To calculate the partial pressures of Cl2 (PCl2) and O2 (PO2) in the high temperature corrosion cell, you will need to follow these steps:

1. Start by converting the given concentration of O2 to partial pressure. The partial pressure of O2 (PO2) can be calculated using the ideal gas law equation: PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.

2. Convert the concentration of O2 from vol% to mol fraction. Since the volume percent (vol%) is given, you can convert it to mol fraction (x) by dividing the volume of O2 by the total volume of the system.

3. Use the mol fraction of O2 to calculate the partial pressure of O2. Multiply the mol fraction of O2 obtained in the previous step by the total pressure of the system to get the partial pressure of O2 in the cell.

4. Repeat steps 2 and 3 for HCl. Convert the concentration of HCl from vppm (volume parts per million) to mol fraction, and then calculate the partial pressure of HCl.

5. To find the partial pressure of Cl2, use the Deacon Process equation: 4HCl(g) + O2(g) = 2Cl2(g) + 2H2O(g). Since the stoichiometric ratio is 2, divide the partial pressure of HCl by 2 to get the partial pressure of Cl2.

6. Plot log PCl2 and log PO2 on the Y-axis and X-axis, respectively, using the given thermodynamic phase diagram. Compare the calculated values of PCl2 and PO2 with the diagram to determine the corresponding points on the diagram.

By following these steps, you should be able to calculate the partial pressures of Cl2 (PCl2) and O2 (PO2) from the available data in the high temperature corrosion cell.