The equilibrium constant Kc for the following reaction is equal to 0.20 at 250°C. Calculate the equilibrium constant Kp for the reverse reaction at the same temperature.
COCl2 (g) = CO (g) + Cl2 (g)
My Answer:
To find the reverse reaction of Kc, it should be 1/0.2 = 5, so the new Kc is 5 for the reverse reaction.
Delta G is also = -1 in the reverse reaction
So Kp = 5* (0.08206 * 523K)^-1
Kp = 0.116
I wanted to check if this was correct
Looks ok to me. Good work.
Your calculation is almost correct.
To find the equilibrium constant Kp for the reverse reaction at the same temperature, you need to use the equation:
Kp = Kc * (RT)Δn
In this equation, Δn represents the change in the number of moles of gas between the products and reactants.
For the forward reaction:
COCl2 (g) = CO (g) + Cl2 (g)
There are 2 moles of gas on the reactant side and 1 mole of gas on the product side. Therefore, Δn = 1 - 2 = -1.
Now plug in the values into the equation:
Kp = 0.2 * (0.08206 * 523 K)^-1 * (-1)
Kp = 0.2 * 0.001 (%85=) 0.0002
So the correct value for Kp for the reverse reaction is 0.0002.
To calculate the equilibrium constant Kp for the reverse reaction at the same temperature, you need to use the relationship between Kp and Kc.
The equilibrium constant Kc is equal to the molar concentrations of the products divided by the molar concentrations of the reactants, each raised to the power of their respective stoichiometric coefficients. In this case, the equilibrium constant Kc for the given reaction COCl2 (g) = CO (g) + Cl2 (g) is equal to 0.20 at 250°C.
To find the equilibrium constant Kp for the reverse reaction, you can use the relationship Kp = Kc(RT)^(Δn), where R is the gas constant, T is the temperature in Kelvin, and Δn is the difference in the number of moles of gaseous products and reactants.
In this case, the reverse reaction is CO (g) + Cl2 (g) = COCl2 (g) with a stoichiometric coefficient of -1 for COCl2 (g) and coefficients of 1 for CO (g) and Cl2 (g). Therefore, Δn = (-1) - (1 + 1) = -3.
Given that Kc = 0.20 and the temperature is 250°C, you need to convert the temperature to Kelvin by adding 273.15. So, T = 250 + 273.15 = 523.15 K.
Now, you can calculate Kp using the equation Kp = Kc(RT)^(Δn). Given that R is the ideal gas constant (0.08206 L·atm/(mol·K)), you can substitute the values:
Kp = 0.20 * (0.08206 L·atm/(mol·K)) * (523.15 K)^(-3)
Kp ≈ 0.116
So, the calculated value for Kp is approximately 0.116.