Textbook Problem 5I.13

[TiaPayne1F]

In the solution manual, it uses the Kc value from the table for the K value. When I was originally solving the problem, I was using the K value at 1000 K because all the components of the equation are gases, and the problem asks for K. Shouldn't the Kp values be used, instead of Kc? Why did they use Kc in the solutions?

[Daniel Lee 2J]

Despite all the components of the equation being gases, they still have concentrations as well as partial pressures. So it's better to use kc in this example because the values given to you are already in mmols and liters. You could use these to find individual concentrations, rather than solving for the partial pressures. Make sure to use what is less work for you instead of depending on the state of the reactant/product!