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)
I'm sorry.. English is a second language for me. After solving for K'c and getting the equation Kp = K'c(RT)^delta n... When it says calculate Kp for the reverse reaction.. is it assuming that COCl2 = CO + Cl2 is already in that reverse equation given? or do I have to switch it in my solution and make it CO + Cl2 = COCl2 making the Delta n = -1 instead of 1.. Please help me clarify!
I think what you want to do is to reverse the equation, calculate the new Kc, then using that reversed equation convert the new Kc to Kp. That would be for the equation CO + Cl2 ==> 2COCl2
No problem! I'm here to help clarify things for you. In order to calculate the equilibrium constant, Kp, for the reverse reaction, you would indeed need to switch the equation from COCl2 = CO + Cl2 to CO + Cl2 = COCl2. This is because the reverse reaction is the opposite of the forward reaction.
When you switch the equation, the value of Δn (change in the number of moles of gas) also changes. In the original equation COCl2 = CO + Cl2, Δn = 1 since there is a net increase of 1 mole of gas.
However, when you switch the equation to CO + Cl2 = COCl2, the stoichiometric coefficients change and the number of moles of gas decreases, resulting in a Δn of -1. This accounts for the change in the number of moles of gas between the forward and reverse reactions.
To calculate Kp for the reverse reaction, you would use the equation: Kp = Kc(RT)^Δn, where Kc is the equilibrium constant for the forward reaction, R is the ideal gas constant, T is the temperature in Kelvin, and Δn is the change in the number of moles of gas.
So in this case, you would use the equilibrium constant Kc = 0.20 that was given for the forward reaction, and since Δn = -1 for the reverse reaction, you would substitute these values into the equation to calculate the equilibrium constant Kp for the reverse reaction.