In a study of the following reaction at 1200K it was observed that when the equilibrium partial pressure of water vapor is 15.0 torr, the total pressure at equilibrium is 36.3 torr.
3Fe(s)+4H2O(g) (reversible arrows) Fe3O4(s)+4H2(g) Calculate the value of Kp for this reaction at 1200K. Hint: Apply Dalton's Law of partial pressures.
Ptotal = PH2 + PH2O = 35.3 torr.
Solve for PH2.
Write the equilibrium equation expression for Kp = ??
Then substitute these values into the equation. Don't forget to change the pressures to atmospheres.
Post your work if you get stuck.
Check the typo I made. That's 36.3 torr total pressure.
Thank you so much!!!
To calculate the value of Kp for the given reaction, we need to follow the steps provided.
Step 1: Solve for PH2
Given that the total pressure at equilibrium (Ptotal) is 36.3 torr and the equilibrium partial pressure of water vapor (PH2O) is 15.0 torr, we can use Dalton's Law of partial pressures to find the equilibrium partial pressure of hydrogen gas (PH2).
Ptotal = PH2 + PH2O
Substituting the given values:
36.3 torr = PH2 + 15.0 torr
Solving for PH2:
PH2 = 36.3 torr - 15.0 torr
PH2 = 21.3 torr
Step 2: Write the equilibrium equation expression for Kp
The equilibrium expression for Kp is written using the partial pressures of the reactants and products. For the given reaction:
Kp = (PH2)^4 / (PH2O)^4
Step 3: Substitute the values into the equation
Substituting the values obtained in Step 1:
Kp = (21.3 torr)^4 / (15.0 torr)^4
Kp = (21.3/15.0)^4
Kp ≈ 4.523
Note: Remember to convert the pressures to the same units (torr or atm) before substituting them into the equation.
Therefore, the value of Kp for this reaction at 1200K is approximately 4.523.
To calculate the value of Kp for the given reaction at 1200K, we need to use Dalton's Law of partial pressures and the given equilibrium partial pressure values.
First, we know that the total pressure at equilibrium is 36.3 torr and the equilibrium partial pressure of water vapor is 15.0 torr. From Dalton's Law, we can calculate the partial pressure of hydrogen gas (H2) at equilibrium.
Ptotal = PH2 + PH2O
Rearranging the equation to isolate PH2:
PH2 = Ptotal - PH2O
Substituting the values:
PH2 = 36.3 torr - 15.0 torr
PH2 = 21.3 torr
Next, we need to write the equilibrium equation expression for Kp. For the given reaction:
3Fe(s) + 4H2O(g) ↔ Fe3O4(s) + 4H2(g)
The equilibrium constant expression in terms of partial pressures is:
Kp = (PH2)^4 / (PH2O)^4
Substituting the calculated values:
Kp = (21.3 torr)^4 / (15.0 torr)^4
Lastly, remember to convert the pressures to atmospheres, as Kp is typically expressed in terms of atmospheres. We can convert torr to atm by dividing by 760 torr/atm.
Kp = (21.3 torr / 760 torr/atm)^4 / (15.0 torr / 760 torr/atm)^4
Simplifying the expression:
Kp = (0.02797 atm)^4 / (0.01974 atm)^4
Kp = 0.0000295 / 0.00000245
Calculating the final value:
Kp ≈ 12.04
Therefore, the value of Kp for this reaction at 1200K is approximately 12.04.